The invention discloses an intelligent driving system of a street lamp based on an LED array, comprising a bridge rectification circuit, a quasi-resonance period DC/DC conversion circuit, an LED illumination module circuit, a current/voltage detecting circuit, a photoelectric insulation circuit, a microprocessor and a microprocessor peripheral circuit. Compared with the prior art, the intelligentdriving system of the street lamp based on the LED array utilizes the microprocessor to control and manage the photoelectric heat dynamic characteristic of an LED, thereby improving the working reliability of the LED and achieving the energy-saving purpose. The invention also provides an energy-saving control method of a street lamp, which enables the intelligent driving system of the LED street lamp to make adaptation and adjustment according to the luminescence characteristic change caused by the change of exterior conditions such as working temperature, and the like so as to achieve optimal illumination effect and optimize the illumination efficiency of an LED street lamp system.