In order to solve the problem of long operation time and low success rate of pedicle screw placement in spinal fusion，a method for automatic planning of pedicle screw automatic path was obtained by the improvement of LEE method. With this method，the possible screw insertion point and the end point are selected in the three- dimensional space，and then the optimal path of the screw placement is obtained through the error path exclusion， safety evaluation，and the depth of insertion. Finally，the incident angle of the optimal path is determined. The experimental results show that the proposed method is better than the LEE method，which can make the pedicle screws have better mechanical properties. At the same time，the parameters of the incident point can provide a theoretical basis for the operation