The traditional analysis method is not practical in the power prediction and parameter optimization analysis of low temperature differential Stirling engine. In order to predict the output power of low temperature differential Stirling engine quickly, this paper studied the application of the second order Simple model in the thermodynamic cycle analysis of low temperature differential Stirling engine. It described the simplified structural model of low temperature differential Stirling engine and the temperature characteristics of internal working medium. Based on Simple model, this study derived the actual heat transfer equation of non-ideal heat exchanger in low-temperature differential Stirling engine, and analyzed the heat return loss, pumping loss and actual heat transfer of heat exchanger. The variation of the temperature, pressure and energy of the working medium in the low-temperature differential Stirling engine system with the crank Angle was illustrated by examples, and the theoretical output power of the low-temperature differential Stirling engine was analyzed. The actual output power of low temperature differential Stirling engine at different heating temperatures was compared with the calculated power of Simple model. The comparison results show that the error between the output power calculated by the Simple model and the actual output power is small, indicating that the Simple model is in good agreement with the actual cycle of the low-temperature differential Stirling engine. In order to study the influence of regenerator on engine performance of low temperature difference Stirling engine, the paper optimized the structure of regenerator of low temperature difference Stirling engine. The output power of the regenerator after optimization was compared with that before optimization. The comparison results show that after optimizing the regenerator, the actual output power of the low-temperature differential Stirling engine and the calculated power of the Simple model are both increased by 20%. It is shown that optimizing the structure of regenerator is an effective method to improve the performance of low temperature differential Stirling engine. © 2023 South China University of Technology. All rights reserved.