针对喷油器在使用过程中由于精密偶件结构参数的变化引起喷油量及泄油量发生变化的问题，以博世CRIN2/3喷油器为研究对象，基于喷油器精密偶件磨损对喷油及泄漏影响的理论分析，利用AMESim软件构建喷油器仿真模型。采用BoxBehnken设计方法，以柱塞偶件间隙、针阀偶件间隙、针阀升程为试验因子，以喷油量与泄油量为试验指标，建立了各试验因子与试验指标间的回归模型，分析了各因子对试验指标的影响规律。采用多目标优化法得出如下结论：当柱塞偶件间隙范围为3.00~3.07 μm，针阀偶件间隙范围为1.50~1.77 μm，针阀升程范围为0.32~0.38 mm时，能够实现在喷油量变化率满足国标的要求下，泄漏量达到最小。

For the change of fuel injection and discharge quantity led by the change of structural parameters for precision pair during the process of injector working, the injector simulation model was built by taking Bosch CRIN2/3 injector as the research object with AMESim software based on the theoretical analysis for the effects of fuel injector precision pair wear on fuel injection and leakage. Then the regression model between test factor and test indicator was established with the BoxBehnken design method by designing the plunger coupler gap, the needle valve gap and the needle valve lift as test factors and taking the fuel injection amount and leakage amount as test indicators, and the influences of each factor on test indicators were further analyzed. The multiobjective optimization method was used to conclude that the smallest leakage amount was obtained and the change rate of fuel injection could meet the requirements of national standards when the plunger coupler gap range was 3.00~3.07 μm, the needle valve coupler gap range was 1.50~1.77 μm, and the needle valve lift range was 0.32~0.38 mm.