In order to solve the problems of low interactive efficiency, high learning threshold and poor reduction accuracy of the manual trajectory planning of the existing lower limb fracture reduction robot, I propose an interactive solution to help doctors easily and accurately control the 3D model for trajectory planning. The solution includes two parts, hardware and software. The hardware is a handle controller, which can establish a reasonable mapping relationship between the 3D model and the human hand and enable doctors to operate the model through simple buttons and joysticks to achieve the movement of the target bone fragments. The software is a PC console program, which can provide quantitative visual feedback and clearly display the user's workflow.