The invention discloses a system for testing an anti-fog function of a video device. The system comprises an airtight haze environment test box, a haze generation chamber and a haze waste gas treatment chamber are arranged on the outside of the haze environment test box, a tripod head is arranged on the outside of the haze environment test box, the video device is installed on the tripod head, a turbine air circulation fan, an anti-deposition fan, a movable guide rail and a movable objective table are arranged on the bottom surface of the inside of the haze environment test box, a lamp box is arranged on the side, right opposite to the video device, of the movable objective table, a test graphic card is installed on the lamp box, an illumination lamp is arranged at the top of the inside of the haze environment test box, and an air exchange device and a sealing push-pull door are arranged on the top surface of the outside of the haze environment test box. The system solves the problems that an existing anti-fog test device can only test in a fixed point and cannot test in a dark chamber environment and provides a flexible and effective test method for researches of anti-fog capacity of the video device.