The present invention provides a transformer moisture absorber smoothness testing device with high working efficiency. The device comprises a first valve body, a second valve body, a pump pipe, a piston assembly, springs, steel balls, a self-tapping screw and a second self-tapping screw. The first valve body is provided with a mounting connection hole, a breathing vent hole, an inflation vent hole and a pump pipe mounting hole. The second valve body is provided with a first bolt hole, a first spring steel ball mounting hole, a first air guide hole, a second spring mounting hole, a second bolt hole, an air out hole and a second air guide hole. The pump pipe is fixed installed in the first valve body. The piston of the piston assembly is sleeved with a sealing ring and then is movably arranged in the pump pipe. Two groups of springs and two groups of steel balls are fixedly installed in the second valve body by the self-tapping screw and the second self-tapping screw. The second valve body and the first valve body are fixedly connected, and corresponding air holes communicate mutually. The device has the advantages of simple structure, low cost, small size, light weight, and easy carrying and installation, whether a moisture absorber is smooth is tested, and compared with a traditional method, the working efficiency is greatly improved.