Abstract: Based on the analysis of self-adaptive functional structure of stopper in different working stages, some main problems of stopper were found with motion simulation analysis by using ADAMS software, and then a stopper was optimized and designed with self-adjustable structure without overconstraints. Simulation results showed that the performance of the stopper was improved with the benefit of more reliable working process. Meanwhile, the ability of self-adjustment and self-adaptation was advanced for eliminating the sensitivity to environment. It is indicated that the self-adjustable structure of mechanism has the engineering practical value and great prospect.