The invention relates to a digitalized electronic speed regulator. The digitalized electronic speed regulator comprises a rotating speed controller, a rotating speed sensor, an actuator and cables, wherein the rotating speed controller sets the desired rotating speed, the rotating speed sensor collects the practical rotating speed, the actuator regulates the practical rotating speed, and the cables are connected with the rotating speed controller, the rotating speed sensor and the actuator. The rotating speed controller further comprises a rotating speed setting potentiometer, a comparator, a rotating speed deviation device, a converter and a PID regulator, wherein the rotating speed setting potentiometer sets the desired rotating speed, the comparator compares the desired rotating speed with the practical rotating speed, the rotating speed deviation device calculates rotating speed deviation value of the desired rotating speed and the practical rotating speed, the converter converts the practical rotating speed into a digital square wave, and the PID regulator converts the rotating speed deviation value into PWM. The invention further provides an engine speed regulation method. The digitalized electronic speed regulator and the engine speed regulation method have the advantages that a power system is safer in operation and running, the dispersion performance is better, and the stability is better.