EGR valve self-learning method

The invention discloses an EGR valve self-learning method. The activation conditions for EGR valve self-learning include that an ECU power switch is powered off or powered on, and the actual mileages of a whole vehicle is greater than the mileage preset in an ECU. In addition, an EGR valve uses PWM duty ratio as a control signal, adopts an open-loop control mode and is slowly opened or closed completely. By means of the EGR valve self-learning method, the self-learning value accuracy can be effectively improved, and the EGR valve control accuracy and working reliability are ensured.