Abstract: It is necessary to detect the defects of the stainless steel heat exchange tubes of the condenser which have been operated for a period of time, and the most effective way to detect the defects of the stainless steel heat exchange tubes of the condenser is manual detection. Although it is simple, but the workload is too large, so we design a robot to replace the manual to detect the heat exchanger tubes, improve efficiency and reduce labor intensity. Through the comparison of different ways, the robot with rising feet is selected for design. The robot can automatically move on the tube plate of the heat exchange tube to be detected and carry the eddy current probe to detect the tube array. SolidWorks software is used to design the mechanical structure of the robot, including the expansion foot and the moving mechanism of the robot. The robot is established in the simulation environment, and the strength of its motion process is checked to verify the stability of the robot in the motion process.