A physical model of detonation wave propagation process in the detonation combustion chamber is developed on the diagram, based on this a performance parameter calculation method of the pulse detonation engine is made by applying characteristic method, the quantitative relation between performance parameters and structural parameters of the pulse detonation engine is obtained, and structural parameters design method of the pulse detonation engine is established. The calculation examples are used in the design and analysis of the structural parameters of PDE with different thrust levels, this provides theoretical bases for the design and application of pulse detonation engine.