Common rail pipe of diesel engine high pressure common rail fuel injection system was studied, and common rail system structure and working principles were introduced. By using GTFuel analysis software，the system simulation model was established, and the effect of common rail material elasticity modulus on the common rail pressure was analyzed. Simulation results show that，the greater the common rail pipe elasticity modulus，the better inhibitory effect is on rail pressure fluctuation. The inhibitory effect of too much wall thickness on common rail fuel pressure fluctuation is not obvious. The inhibitory effect of too much wall thickness on common rail fuel pressure fluctuation is not obvious. The simulation data provides a theoretical reference for the design，production and simulation of common rail pipe.