Abstract: In clinic,the reduction of intertrochanteric fractures should meet two requirements of alignment and displacement.The existing computer-aided reduction method cannot be well performed.To address this problem,a liner-positional alignment method is presented to reduce intertrochanteric fractures.The input of the method is a 3D triangular surface model of fractured femoral bones.Firstly,to realize the adjustment of liner alignment,the limb alignment is evaluated by making the best of the characteristics of CT scan.Secondly,the positional alignment is executed with the aim of minimizing the distance between fracture surfaces.Finally,pairwise reduction is iteratively performed based on liner and positional alignment.The comparison is drawn between the accuracy of our approach and that of manual reduction.The results show that our method accords with the criteria of clinical reduction,and effectively improves the efficiency of preoperative planning for femoral intertrochanteric fractures.