A dustproof gate valve includes a housing having a first panel, a second panel, and a valve port on each of the first and second panels, a slide including a body and a valve member and drivable to move between a first position and a second position, the slide closing the valve port of the first panel when at the first position, a driver mounted in the housing, a swing arm having one end thereof connected to the driver for moving the slide, and a dust pipe mounted in said body. When the slide is at the second position, the dust pipe is disposed between the valve port of the first panel and the valve port of the second panel, and the pipe wall of the dust pipe separates the valve ports of the first and second panels from the accommodation space.