Abstract: In this paper, different strategies of fuel flow control are proposed for the fuel system to maintain the stability of oil pressure in the fuel injection pipe. Firstly, assuming the fuel system’s related parameters are in an ideal setting so that the patterns of fuel pressure changes with time can be observed briefly, and then basing on the relationship among the pressure, fuel density and flow rate of fuel injection, a mathematical model used to illuminate the fuel pressure fluctuation in the fuel pipe could be established by using infinitesimal method. Secondly, for the fuel system with a cam and a needle valve, the equations of oil entry and injection are modified based on cam’s rotation principle and analysis of factors affecting fuel injection. Meanwhile, an optimized model of minimizing fuel pressure fluctuation in the fuel pipe is also established to get the optimal cam angular velocity. Finally, a double-injection-nozzles-linkage scheme is proposed to optimize the pressure fluctuation. The knowledge of hydromechanics is also applied here to simplify the model.