an inlet of the de-C4 rectification tower (101) is used for introducing a propane raw material (1), an overhead gaseous phase outlet of the de-C4 rectification tower (101) is connected with a gaseous phase inlet of the propane preheating unit (102), and a tower kettle liquid phase outlet of the de-C4 rectification tower (101) is used for separating C4-containing heavy component liquid (2); an outlet of the propane preheating unit (102) is connected with an inlet of the propane dehydrogenation reaction unit (103), an outlet of the propane dehydrogenation reaction unit (103) is connected with an inlet of the dehydrogenation reaction gas compression unit (104), an outlet of the dehydrogenation reaction gas compression unit (104) is connected with an inlet of the dehydrogenation reaction gas drying unit (105), an outlet of the dehydrogenation reaction gas drying unit (105) is connected with an inlet of the dehydrogenation reaction gas cooling tank unit (106), an outlet of the dehydrogenation reaction gas cooling tank unit (106) is connected with an inlet of the dehydrogenation reactant separation unit (107), a gaseous phase outlet of the dehydrogenation reactant separation unit (107) is connected with an inlet of the pressure swing adsorption unit (301), a liquid phase outlet of the dehydrogenation reactant separation unit (107) is connected with an inlet of the de-C2 rectification tower (108), an overhead gaseous phase outlet of the de-C2 rectification tower (108) is used for yielding C2-containing light component gas (12), a tower kettle liquid phase outlet of the de-C2 rectification tower (108) is connected with a liquid phase inlet of the propyne hydrogenation reaction unit (109), a gaseous phase inlet of the propyne hydrogenation reaction unit (109) is used for introducing hydrogen (14), an outlet of the propyne hydrogenation reaction unit (109) is connected with an inlet of the propane-propylene rectification tower (110), an overhead gaseous phase outlet of the propane-propylene rectification tower (110) is used for yielding a propylene product (16), and a tower kettle liquid phase outlet of the propane-propylene rectification tower (110) is connected with a liquid phase inlet of the propane preheating unit (102);

an inlet of the air compressor (201) is used for introducing air (17), an outlet of the air compressor (201) is connected with an inlet of the cryogenic air separation unit (202), a liquid phase outlet of the cryogenic air separation unit (202) is used for yielding oxygen (20), and a gaseous phase outlet of the cryogenic air separation unit (202) is connected with a first gaseous phase inlet of the nitrogen and hydrogen mixer unit (302); a methane and hydrogen mixed gas outlet of the pressure swing adsorption unit (301) is used for yielding methane and hydrogen mixed gas (22), and a pure hydrogen outlet of the pressure swing adsorption unit (301) is connected with a second gaseous phase inlet of the nitrogen and hydrogen mixer unit (302); and

an outlet of the nitrogen and hydrogen mixer unit (302) is connected with an inlet of the first nitrogen and hydrogen mixed gas compression unit (303), an outlet of the first nitrogen and hydrogen mixed gas compression unit (303) is connected with a first gaseous phase inlet of the nitrogen and hydrogen mixed gas preheating unit (304), an outlet of the nitrogen and hydrogen mixed gas preheating unit (304) is connected with an inlet of the ammonia synthesis reaction unit (305), an outlet of the ammonia synthesis reaction unit (305) is connected with an inlet of the ammonia synthesis reaction gas condensation unit (306), an outlet of the ammonia synthesis reaction gas condensation unit (306) is connected with an inlet of the ammonia synthesis reactant separation unit (307), a gaseous phase outlet of the ammonia synthesis reactant separation unit (307) is connected with an inlet of the second nitrogen and hydrogen mixed gas compression unit (308), an outlet of the second nitrogen and hydrogen mixed gas compression unit (308) is connected with a second gaseous phase inlet of the nitrogen and hydrogen mixed gas preheating unit (304), and a liquid phase outlet of the ammonia synthesis reactant separation unit (307) is used for yielding a liquid ammonia product (28).

introducing a propane raw material (1) into a de-C4 rectification tower (101) to separate C4-containing heavy component liquid, wherein C4-containing heavy component liquid is yielded from a tower kettle of the de-C4 rectification tower (101), while C3-containing light component gas (3) is yielded from a tower overhead of the de-C4 rectification tower (101);

introducing the C3-containing light component gas (3) and recycled propane (4) from a tower kettle of a propane-propylene rectification tower (110) into a propane preheating unit (102) and being heated to yield gaseous phase propane (5);

introducing the gaseous phase propane (5) into a propane dehydrogenation reaction unit (103) to undergo a propane dehydrogenation reaction, and introducing yielded propane dehydrogenation reaction gas (6) into a dehydrogenation reaction gas compression unit (104) to be compressed, and introducing yielded dehydrogenation reaction compressed gas into a dehydrogenation reaction gas drying unit (105) for dehydration, and introducing the yielded dehydrogenation reaction dried gas (8) into a dehydrogenation reaction gas cooling tank unit (106) to be cooled and condensed, a yielded condensation product (9) entering a dehydrogenation reactant separation unit (107) to be subjected to flash separation, where hydrogen-containing tail gas (11) is yielded from a tower overhead of the dehydrogenation reactant separation unit (107), and C2/C3-containing liquid (10) and hydrogen-containing tail gas (11) is yielded from a tower bottom of the dehydrogenation reactant separation unit (107);

introducing the C2/C3-containing liquid (10) into a de-C2 rectification tower (108) for rectification and separation, where C2-containing light component gas (12) is yielded from a tower overhead of the de-C2 rectification tower (108), while first C3-containing liquid (13) is yielded from a tower kettle of the de-C2 rectification tower (108); and introducing the first C3-containing liquid (13) and first hydrogen (14) to a propyne hydrogenation reaction unit (109) for a propyne hydrogenation reaction, and introducing second C3 liquid (15) yielded from the propyne hydrogenation reaction to a propane-propylene rectification tower (110) for rectification and separation, where a propylene product (16) is yielded from a tower overhead of the propane-propylene rectification tower (110), while recycled propane (4) is yielded from a tower kettle of the propane-propylene rectification tower (110);

compressing air (17) through an air compressor (201), and introducing compressed air (18) to a cryogenic air separation unit (202) for rectification and separation to yield nitrogen (19) and oxygen (20);

introducing the hydrogen-containing tail gas (11) yielded from the tower overhead of the dehydrogenation reactant separation unit (107) to a pressure swing adsorption unit (301) for separation to yield second hydrogen (21) and methane and hydrogen mixed gas (22);

introducing the nitrogen (19) and the second hydrogen (21) to a nitrogen and hydrogen mixer unit (302) to be uniformly mixed, compressing yielded mixed gas (23) of nitrogen and hydrogen through a first nitrogen and hydrogen mixed gas compression unit (303) to obtain mixed compressed gas (24) of nitrogen and hydrogen, heating the mixed compressed gas (24) of nitrogen and hydrogen and pressurized recycled mixed gas (30) of nitrogen and hydrogen yielded from a second nitrogen and hydrogen mixed gas compression unit (308) in a nitrogen and hydrogen mixed gas preheating unit (304), introducing high-temperature mixed compressed gas (25) to an ammonia synthesis reaction unit (305) for an ammonia synthesis reaction, introducing yielded ammonia synthesis reaction gas (26) to an ammonia synthesis reaction gas condensation unit (306) to be cooled and condensed to obtain low-temperature ammonia synthesis reactant (27), introducing the low-temperature ammonia synthesis reactant (27) to an ammonia synthesis reactant separation unit (307) for flash separation to yield a liquid ammonia product (28) and recycled mixed gas (29) of nitrogen and hydrogen; and introducing the recycled mixed gas (29) of nitrogen and hydrogen to a second nitrogen and hydrogen mixed gas compression unit (308) to be compressed to yield pressurized recycled mixed gas (30) of nitrogen and hydrogen.