The flexible selection of the working section about the camshaft profile for the double valve fuel injection system has a great impact on the injection process and the average cycle injection quantity.Taking the pre-injection opening pressure,the main injection opening pressure,the main injection peak pressure and the average cycle injection quantity as the evaluation indexes,the orthogonal test and range analysis method were selected to study the multiple injection characteristics.The primary and secondary factors affecting different evaluation indexes and the optimal combination scheme were obtained.Considering the injection pressure and the average circulating injection quantity as comprehensive evaluation indexes,and according to the comprehensive balance method,a comprehensive balance scheme with multiple evaluation indexes was obtained,which were the oil supply timing for 156 °CaA,the pre- injection timing for 161 °CaA,the main injection timing for 177 °CaA and the cam speed for 500 r/min.Based on the comprehensive balance optimization scheme,it was studied on the influence of the change of the interval of the pre-injection and the main injection on the average circulating fuel injection quantity.The nonlinear fluctuation law of the average circulating fuel injection quantity was obtained,and the characteristics of the change of the main injection opening pressure were verified.