For pseudo-shock characteristics in the two-dimensional supersonic inlet diffuser，the influences of the diffuser length

diffusing ratio and the center line offset were numerically studied. Results show that: within the scope of the study

the influences of the diffuser length and diffusing ratio on the pseudo-shock characteristics are more significant than the center line offset. Both the diffuser length and diffusing ratio affect the pseudo-shock characteristics by changing the shock train length and the scale of separation. Based on the numerical results of a series of diffuser geometries

a simple linear fitting formula to estimate the optimum diffusing ratio corresponding to the maximum diffusion performance has been proposed. These results are beneficial to the design of the supersonic inlet diffuser.