A system, comprising: a fuel injection system with multiple valves; an electronic unit pump disposed in the fuel injection system with multiple valves, the electronic unit pump operable to output high pressure fuel; a low-pressure fuel pipe disposed in the fuel injection system with multiple valves, the low-pressure fuel pipe operable to input fuel into plunger hole of the claimed electronic unit pump; a supply cam disposed in the fuel injection system with multiple valves, the supply cam operable to generate high pressure fuel by pushing the plunger of the claimed electronic unit pump; at least two electronic injectors disposed in the fuel injection system with multiple valves, the electronic injectors operable to inject fuel; high pressure fuel injection pipes; electronic control unit operable to connect the claimed electronic unit pump and the claimed electronic injectors respectively to control the opening and closing of the solenoid valve of the claimed electronic unit pump and the claimed electronic injector; the electronic unit pump consists of plunger and solenoid valve controlling low-pressure fuel pipe on-off; the claimed electronic control unit chooses electronic fuel injector for fuel injection according to the engine firing sequence and fuel injection timing; then by controlling the opening and closing operation timing of the solenoid valves in the electronic unit pump and the corresponding electronic fuel injector, the injections timing, injection pressure of the electronic fuel injector and fuel injection duration can be controlled; characterized in that the high pressure fuel injection pipes are operable to connect the claimed electronic unit pump and the claimed electronic injectors to transport the high pressure fuel outputted by the claimed electronic unit pump to the claimed electronic injectors; and in that the solenoid valve of the claimed electronic unit pump opens to make the fuel in the high pressure fuel injection pipe reflux into the low pressure fuel pipe when the oil pressure in the high pressure fuel injection pipe exceeds then predefined threshold. a fuel injection system with multiple valves; an electronic unit pump disposed in the fuel injection system with multiple valves, the electronic unit pump operable to output high pressure fuel; a low-pressure fuel pipe disposed in the fuel injection system with multiple valves, the low-pressure fuel pipe operable to input fuel into plunger hole of the claimed electronic unit pump; a supply cam disposed in the fuel injection system with multiple valves, the supply cam operable to generate high pressure fuel by pushing the plunger of the claimed electronic unit pump; at least two electronic injectors disposed in the fuel injection system with multiple valves, the electronic injectors operable to inject fuel; high pressure fuel injection pipes; electronic control unit operable to connect the claimed electronic unit pump and the claimed electronic injectors respectively to control the opening and closing of the solenoid valve of the claimed electronic unit pump and the claimed electronic injector; the electronic unit pump consists of plunger and solenoid valve controlling low-pressure fuel pipe on-off; the claimed electronic control unit chooses electronic fuel injector for fuel injection according to the engine firing sequence and fuel injection timing; then by controlling the opening and closing operation timing of the solenoid valves in the electronic unit pump and the corresponding electronic fuel injector, the injections timing, injection pressure of the electronic fuel injector and fuel injection duration can be controlled;