The invention provides an intelligent dimming control system, which includes a controller, at least one bus connected with the controller, and a plurality of HID drivers connected with the bus. The controller includes a control module, a clock module controlling the output time of a control command of the control module, an acquisition module providing environment temperature data to the control module, and a first communication chip sending the control command of the control module. A communication module is built in any one of the HID drivers and includes a second communication chip receiving the control command and a conversion module converting the control command received by the second communication chip to be identifiable by the HID driver. According to the invention, the output control of a plurality of supplementary lighting devices can be realized by the use of one controller for cooperating with the built-in communication module of the product, and the needs of supplementary lighting for common facilities such as an agricultural greenhouse are met. Meanwhile, the controller can operate automatically after working parameters are set, and unattended operation can be realized.