A bench test was made by installing the fuel injection pump on a highpressure common rail system. Results of the test show that the ECU is able to collect data from the sensor and communicate with PC and drive actuator. In addition, it controls rail pressure by using a closedloop and highprecise injection quantity measurement. In different engine operating conditions, the fluctuation of measurement of pressure test is about ±2%. PID control results are in basic agreement with the control requirements in rail pressure fluctuation test. Rail pressure switch is completed in 0.1 s in different engine operating conditions. The ECU collect speed signal and throttle signal firstly and then make judgment, and get a new target value by checking the MAP, and make PID regulation in the different condition of engine operating. 