In this paper,the topology optimization design of thermo-mechanical coupling structures is investigated based on the reliability constraint and by taking into consideration the uncertainties of physical parameters,geometric dimensions and loading environments of actual structures,especially the instability of the temperature field. In the investigation,first,a reliability index is obtained by means of the first-order second-moment method and is used to describe the impact of parameter uncertainty. Next,the minimum structural flexibility and the maximum output displacement are respectively chosen as the objective function to establish the topology optimization model of thermo-mechanical coupling structures,with the reliability index as the constraint. Then,the proposed model is solved based on the adjoint sensitivity analysis and the Optimality Criteria algorithm,and the correctness and applicability of the model are finally validated by numerical examples. The results show that,as compared with the deterministic topology optimization design,the proposed method based on reliability constraint is more effective in achieving the best combination of economy and security in a structure and obtaining better design results of compliant mechanisms.