In order to enrich teaching methods of micro control unit (MCU) technology,a multifunction MCU smart car system used for better teaching was designed and realized.The system chooses P89V51,which belongs to classic 51 series MCU.The smart car was equipped with stepped motors to realize the precise control of vehicle movement,such as moving a certain distance or moving toward a certain direction.It is different from other smart cars with single function,which was only designed for competition of speed.Like controlling the direction and distance of vechicle’s motion and avoiding obstacles,relevant experiments were designed for students to review what they learned about micro control unit technology.Three different kinds of infrared optoelectronic devices,namely the infrared transmitter TSAL6200,integrated receiver LL M6038 and infrared phototransistor 3DU5C,were used to detect the surrounding environment around the car.On this platform,programming to realize all these functions will help students consolidate and deepen the theories they learned on the book.