In the tube-fin heat exchanger air-pressure expansion technology,the research on the pull-out force of the internally threaded copper tube and the polyurethane sealing ring is a very critical part.The pull-off force test was verified through the self-designed and improved test platform.Compared with the ANSYS simulation data,the MATLAB processed test data are basically consistent with the simulation results,it provides reference for the pull-off force of seals and the copper pipes related to swelling.So the designed test model and the built test platform are feasible,and can provide a solution for the engineering application and pull-out force test of the pneumatic tube expander.