Abstract: The replacement of disc cutter is an important part of the operation of shield machines. To achieve automated tool changing operations under complex working environment, frequent interference, and limited view conditions, this paper conducts research on path planning for tool changing robots. First, a robot tool changing operation plan and the robot body mechanism are proposed, and the problems of path planning for the tool changing robot are described. Second, a mathematical model of the robot is built and a method for calculating the target pose is developed. Then, to achieve path optimization, a collision detection method based on distance judgment, a random point generation strategy under target oriented constraints, a redundant path point deletion strategy, and a B-spline curve path smoothing processing strategy are proposed. Finally, a simulation platform for the tool changing robot is built and the algorithm is simulated and analyzed. The results validate the effectiveness of the proposed method.