a lamp board (1), which has a light emitting side (11) and a backlight side (12), and at least one mounting hole (131) is provided in the lamp board;

a lens (2), which is arranged on the light emitting side (11), and the lens (2) has a near light side portion (21) close to the lamp board (1), and at least one first connector (3) is provided on the near light side portion (21) corresponding to a position where the at least one mounting hole (131) is provided;

a radiator (4), which is arranged on the backlight side (12), and at least one second connector (5) is arranged on the radiator (4) corresponding to the position where the at least one mounting hole (131) is provided; and either of the at least one first connector (3) and the at least one second connector (5) extends through the at least one mounting hole (131) and is detachably connected with the other; and

a frame (6), which is rotatably arranged on the radiator (4), and is rotatable against the radiator (4), and is rotatable to a fixed position and a dismounting position; when the frame (6) is in the fixed position, the frame (6) abuts against the lens (2), so the lens (2) moves in a direction close to the radiator (4); and when the frame (6) is in the dismounting position, the frame (6) is separated from the lens (2) to avoid the lens (2) being detached from the radiator (4).