The invention relates to an efficient fence cleaning device of a ventilation port cover for a spraying workshop. The device comprises a base; mounting grooves are formed in the front side and the back side of the base; limiting plates are arranged on the left sides of the mounting grooves; gathering frames are respectively arranged on the right sides of the mounting grooves, and are connected with cylinders; a motor is mounted at the middle part of the left side of the base, and is connected with a turning rod; the turning rod consists of transverse frames and connecting rods; an output shaft of the motor is connected to the center position of the transverse frame at the mostleft end; the connecting rods are arranged between two adjacent transverse frames, and are arranged in the horizontal direction in a left-right staggering manner; each connecting rod is provided with a base frame; the base frames are mounted on the base in a longitudinal sliding manner; and brushes are respectively mounted at one ends, deviated from the center of the base, of the base frames. The device automatically drives two rows of brushes to correspondingly clean all fences on two ventilation port covers in a reciprocating motion manner to achieve high-efficiency automatic cleaning effect based on fixed mounting function of two ventilation port covers.