In this paper，the axia1 compression-open disp1acement re1ation at the fracture point of the neck is tested for the femora1 neck of the body by three type of interna1 fixation pins (compression-screw，Steimann pin，triang1e pin). The axia1 compressioìl-twist ang1e of one cross section rotation to the other at the fracture point of the neck is a1so obtained. The performance of the three types of interna1 fixation stee1 pin are compared，and the mechaniea1 ana1ysis of the interna1 fixation stee1 pin is given.