As the diesel engine industry continues to pursue low fuel consumption and emission standards become more stringent,the fuel injection control of the high-pressure common rail injection system is required to be more accurateIt is of great significance to study the fuel injection deviationThe test platform and simulation model of high injection rate common rail system were established The structural parameters of the system in different numerical ranges and the fuel injection deviation under different working conditions were studiedThe influencing factors and variation law of fuel injection deviation of the system were analyzed through simulation methodThe following conclusions are obtained:when the diameter of oil inlet orifice is (0.22 ± 0.002)mm,the diameter of oil outlet orifice is (0.28 ± 0.003) mm,the diameter of control plunger is (4.3 ± 0.03)mm,and the half cone angle of needle valve is (30.5 ± 3) °,the absolute value of fuel injection deviation rate under the conditions of 40 MPa rail pressure and 0.4 ms pulse width is less then 8%; when the needle valve seal diameter is (2.4 ± 0.06)mm,the needle valve spring preload is (32 ± 4)N,and the pressure chamber inlet diameter is (1.5 ± 0.15)mm,the absolute value of fuel injection deviation rate under 40 MPa rail pressure and 0.8 ms pulse width conditions is less then 8%; when the nozzle diameter range is (0.24 ± 0.02)mm,the absolute value of fuel injection deviation rate under 180 MPa rail pressure and 0.8 ms pulse width conditions is less then 8%