Abstract: The mechanical property test method and device were designed for the performance parameter test requirements of special structure springs. The long-term compress testing and specified load testing of the springs were carried out by the designed method and device. The technical parameters that influenced the reliability and stability of testing results were explored. The steady-going and reliable evaluation methods were constituted based on simulating the structure environment of the spings. The results show that the method and device could evaluate the mechanical properties of the special structure springs accurately.