Gas supply method plays an important role in engine performance for natural gas engines (NGE). In order to overcome the low charging efficiency of pre-mixed fuel gas supply method the multi-point injection (MPI) gas engine controller hardware system is designed in this paper. For the nature gas engine controller the main controller is selected as the microcontroller MC9S12XSl28, then the circuitry for semiconductor piezoelectric air pressure sensor, potentiometer throttle position, thermistor temperature sensor, a magnetic-electric sensor for detecting the top dead center (TDC) and simulating engine speed are designed. What have done above is the base of software design. Key Words: nature gas engine; controller; hardware design