The invention aims to provide a powders pneumatic conveyor trough comprising a powders chamber. The powders pneumatic conveyor trough is characterized in that the left top of the powders chamber is provided with a feed hole, a filter plate is disposed below the powders chamber, the feed hole is provided with a feed valve, compressed gas chambers are arranged below the filter plate, and a compressed gas pipe is disposed below the compressed gas chambers. According to the conveyor trough which inclines, powder enters the powders chamber with a rubber-lined inner wall through the feed valve from a high position, and is conveyed by compressed gas at the bottom. The powders pneumatic conveyor trough is simple and has no need for moving parts, so that the powders crush rarely. A filling sensor is disposed inside the powders chamber; if filling quantity of the powders is high, the sensor allows the feed valve to control conveying speed of powders. Through the design of the powders pneumatic conveyor trough, smooth conveying of the powders is ensured; a telescopic support at the bottom end of the whole powders pneumatic conveyor trough allows tilting angle of the whole powders pneumatic conveyor trough to be adjustable, and tilt can be adjusted according to properties of the powders.