The invention discloses an air purifying device with a self-cleaning function. The air purifying device comprises a base, wherein a purifying machine body is arranged above the base, a purifying device is arranged in the purifying machine body, a horizontal partition plate is arranged in the purifying machine body, the purifying machine body is separated into an upper-layer body and a lower-layer body by the horizontal partition plate, the purifying device is arranged in the upper-layer body, the purifying device comprises an initial filter net, an electrostatic dust removing device and an activated carbon filter layer, the top end of the upper-layer body is provided with a machine cover, a cleaning device, a through hole 1 and a through hole 2 are arranged on the machine cover, the cleaning device comprises a pretreatment device, a dust collecting plate treatment device and a retreatment device, the pretreatment device comprises a first water pipe, a second water pipe and a hydraulic rod, and the dust collecting plate treatment device comprises a controller, a third water pipe and a fixer. The air purifying device can effectively solve the problem proposed in the background technology, can realize the self-cleaning function, has small manual operation pressure, is simple to operate and is worthy of popularization.