The driving controller is the core component of electric vehicle, the performance of which has a direct effect on the performance and transmission efficiency of the electric vehicle. So in this paper a driving controller of electric vehicle based on Freescale S12 MCU is developed for large and medium-sized electric vehicles. An overall design program of driving controller is given according to the special requirements and operating environment of electric vehicle, among them the hardware circuit including the power supply module, the minimum system circuit of controller, the signal conditioning module circuit, the PWM output circuit, data communication module circuit and IGBT driving module circuit and so on; the fuzzy self-tuning PID control strategy is used. And a road test for the electric vehicle installed the driving controller is conducted, which indicates that the driving controller can meet the complex driving conditions, electric vehicle has better acceleration and good speed tracing and meets the relevant national regulations, therefore, the controller is applied to all types of large and medium-sized electric vehicles.