the roller fixing device comprises a support device (1), a fixing rod (2), a fixing beam (3), a first locking nut-bolt pair (4), a second locking nut-bolt pair (5), wherein the support device (1) comprises first guide rails (101), second guide rails (102), mounting holes of bearing on side wall (103), a longitudinal beam (104), and a roller fixing hole (105), and the longitudinal beam (104) is arranged at a top middle position of the support device (1), two first guide rails (101) and two second guide rails (102) are arranged at the top of the support device (1), and two first guide rails (101) are arranged on one side of the longitudinal beam (104), and two second guide rails (102) are arranged on another side of the longitudinal beam (104), and the first guide rails (101) and the second guide rails (102) are symmetrically arranged along the longitudinal beam (104), and two mounting holes of bearing on side wall (103) are respectively provided on two side walls of the support device (1); and the roller fixing hole (105) is arranged on the longitudinal beam (104); and a bottom of the fixing rod (2) is fixedly connected to the support device (1), and the first locking nut-bolt pair (4) and the second locking nut-bolt pair (5) are respectively arranged at two ends of the fixing beam (3), and the fixing beam (3) is arranged on the fixing rod (2) by the first locking nut-bolt pair (4); and

the laser measuring device comprises first moving devices (6), second moving devices (7), a first laser sensor placement plate (8), a second laser sensor placement plate (9), a first laser sensor (10), a first pressing-resistant column (11), a second laser receiving plate (12), a first laser receiving plate (13), a second pressing column (14), a second laser sensor (15), wherein bottoms of two ends of the first laser sensor placement plate (8) are fixedly connected to tops of two first moving devices (6) respectively, and bottoms of two ends of the second laser sensor placement plate (9) are fixedly connected to tops of two second moving devices (7) respectively, and the first laser sensor (10), the first pressing column (11), and the second laser receiving plate (12) are arranged in sequence at the first laser sensor placement plate (8), and the first laser receiving plate (13), the second pressing column (14), and the second laser sensor (15) are arranged in sequence at the second laser sensor placement plate (9), and the first laser sensor (10) matches with the first laser receiving plate (13), and the first pressing column (11) matches with the second pressing column (14), and the second laser sensor (15) matches with the second laser receiving plate (12), and the two first moving devices (6) are respectively arranged on the two first guide rails (101), and the two second moving devices (7) are respectively arranged on the two second guide rails (102); and

the screw driving device comprises a first ball screw pair (17), a first crank (18), a first bearing (19), a first nut (20), a first bolt mounting plate (21), a first nut connecting bolt (22), a second bearing (23), a second ball screw pair (24), a second crank (25), a third bearing (26), a second nut (27), a second bolt mounting plate (28), a second nut connecting bolt (29), a fourth bearing (30), wherein the first crank (18) and the second bearing (23) are respectively arranged at two ends of the first ball screw pair (17), and the first ball screw pair (17) passes through the first bearing (19) and the first nut (20), and the first bolt mounting plate (21) is fixedly connected to the first nut (20); and the second crank (25) and the fourth bearing (30) are respectively arranged at two ends of the second ball screw pair (24), and the second ball screw pair (24) passes through the third bearing (26) and the second nut (27), and the second bolt mounting plate (28) is fixedly connected to the second nut (27); and

a top of the roller to be measured (16) is connected to the fixing beam (3) by the second locking nut-bolt pair (5), and a bottom of the roller to be measured (16) is arranged in the roller fixing hole (105), and the first pressing-resistant column (11) and the second pressing-resistant column (14) are both in contact with the roller to be measured (16), and the first bearing (19) and the third bearing (26) are respectively embedded in the two mounting holes of bearing on side wall (103), and the second bearing (23) and the fourth bearing (30) are both embedded in a bearing mounting hole on the longitudinal beam (104), and the first bolt mounting plate (21) is fixedly connected to a lower disc of the first laser sensor placement plate (8) through the first nut connecting bolt (22), and the second bolt mounting plate (28) is fixedly connected to a lower disc of the second laser sensor placement plate (9) by the second nut connecting bolt (29).