This paper describes a miniature Stirling engine driven by double swash plates. Based on domestic and foreign analysis method of the thermodynamic characteristic theory of the Stirling engine, the establishment of a relevant mathematical model and performance on the numerical analysis were presented. The results include V-t diagrams, P-V diagrams, P-n diagrams, h-n diagrams and the effects of phase angle between the compression and expansion volumes on the engine’s power and efficiency. This paper offers invaluable guide for similar design.