To meet the reliability requirements of thermal actuators, a method for reliability-based topology optimization of thermally actuated compliant mechanisms based on interval non-probabilistic model was proposed. The interval non-probabilistic model was adopted to describe the uncertainties of thermal load. The functional function was constructed by the output displacement of thermally driven compliant mechanisms. The objective function was used to minimize the volume of the thermally actuated compliant mechanisms, and the reliability index was used as the constraint. The model for reliability-based topology optimization of thermally actuated compliant mechanisms based on interval non-probabilistic model was established. The method of moving asymptotes was applied to update the design variables. Compared with the results of deterministic topology optimization, the volume of thermally actuated compliant mechanisms obtained by reliability-based topology optimization was increased, and the reliability index constraints can be effectively met. The theoretical results of thermally actuated compliant mechanisms obtained by reliability design had an error of less than 5% relative to the finite element analysis results. The effectiveness of the proposed design method for thermally actuated compliant mechanisms was demonstrated. The influence of different output stiffness and thermal load intervals on the results of reliability-based topology optimization of thermally actuated compliant mechanisms was analyzed.