Abstract: To develop the leak monitoring system of the pressure pipeline, it is necessary to make all kinds of pores on the stainless steel pipe to get different leak rate, so as to establish the leak quantitative model. Therefore, in this paper, under the condition that the leakage rate is known, the penetration pore size of the stainless steel pipeline under different leakage rate is calculated and studied, and the “leakage rate-aperture” curve is obtained, which provides the theoretical support for the research and development of the leakage monitoring system, guide the processing of the test piece. In this paper, a computational model and analytical correction method are established based on the CFD method to deal with the condition that high-speed jet accompanied by shock wave（or expansion wave） is highly nonlinear under high temperature and high pressure（15.5 MPa）, the curve of “leakage rate-aperture” is obtained, and the accuracy of the result is verified by experiment. The result shows that the error of the CFD calculation is smaller, and the influence of the leakage aperture thickness-aperture ratio and roughness can be considered more accurately.