In order to investigate the aerodynamic noise characteristics of solid rocket engine’s gas, a two-dimensional axi- symmetric mathematical model is established. Large eddy simulation (LES) is applied to simulate the supersonic gas jet flow field of rocket engine. The distribution characteristic of supersonic gas jet noise is obtained based on FW-H surface integral. The calcula- tion results show that the method can capture the flow field structure of complex wave system of supersonic gas jet flow, and the jet noise radiation has obvious directivity.