Objective To investigate the effects of head angle and locking times of locking screws on mechanical properties of the screw-plate system,it provides a theoretical basis for doctors to select locking screws and master the locking times in the course of operation. Methods Selecting locking screws with slight head angle difference and matching with locking compression plates in the case of different locking times,cantilever bending method was used to compare the mechanical properties of each group. Results There are significant differences in failure load and bending stiffness between locking compression plate and locking screw with slight head angle difference(p<0.05),The mechanical properties of the screw-plate system with the best locking degree are the best;There was no significant difference between three times locking and one time locking(p>0.05);The failure modes of locking screw with different head angles and different locking times are different,so the failure mode of locking screw is related to its head angle and locking times. Conclusions The difference of mechanical properties between locking screw with small head angle difference and locking compression plate can not be neglected,It is suggested that doctors should choose locking screw and locking compression plate with the best locking degree in clinical process,and choose the right torque wrench to lock properly many times,these are all designed to prevent the screw loosening affecting patients’ recovery.