A pneumatic conveying type automatic mold powder feeding device belongs to the field of continuous casting process equipment and comprises a large stock bin, a pneumatic conveying device, a middle hopper, an electrically operated valve, a feeding pipe, a small hopper, a screw feeder, a two-dimensional motion mechanism and a base seat. The device uses pneumatic conveying manner to realize remote feeding and to ensure the stock bin to be far away from a continuous caster, thus increasing the storing amount, and the device can allow long-time continuous work; the small hopper, the screw feeder and the two-dimensional motion mechanism are arranged at the lateral wing of a middle tank vehicle, thus avoiding interfering other operations of the worker; the feeding amount can be controlled accurately by gravity blanking and feeding by the screw feeder; the conveying pipeline is completely closed, thus avoiding lag leakage and dust; uniform spreading of large area of mold powder can be realized by the orthogonal coordinate type two-dimensional motion mechanism, and the device is suitable for producing plate blanks and square blanks of different sizes and specifications; the surface quality of steel blanks can be improved by the device, and the device can reduce labor intensity and save the mold powder.