In this study, the behavior of the pressure waves that may occur during high pressure piping rupture are investigated with the various arrangement of adjacent piping. For this purpose, two dimensional CFD analyses were performed with simulating a shock tube which has both high pressure and low pressure side. The rupture disk breaks suddenly, and the pressure wave coming out of the tube exit and collides with the adjacent pipe. High pressure is applied to the pipe at that time and the magnitude of the pressure wave was inversely proportional to the distance from the exit of the shock tube. In order to confirm the tendency of the pipe diameter and position, the differences between the diameter of the adjacent pipe and the distance from the outlet of the shock tube were set as the analysis variable. Based on the results of this study, the structural behavior of the pipe will be confirmed applying the pressure generated around the adjacent pipe in the next study.