Based on the inverse kinematics solution of 6⁃PTRT parallel robot, the constraints on the workspace are analyzed. The three⁃dimensional boundary search method is used to search the workspace in space, and then the simulation is carried out by MATLAB software programming. The shape and distribution characteristics of the workspace are visualized. The workspace volume is solved by polar coordinate search method. The correlation between the structure parameter and the workspace is analyzed by using the control variable method,and the specific effect of the structural parameter on the workspace distribution and volume is clarified. This has important guiding significance for the structural design and practical application of 6⁃PTRT parallel robot.