An efficient centreless grinding machine diamond compact manual grinding turning and centering device is characterized by being composed of a grinding turning and centering hand shank, a movable pin, a pressing bar, screws, a front supporting block, a rear supporting block, a front ejection shaft, a rear ejection shaft, a spring and diamond compacts. The hand shank is connected to the pressing bar through the movable pin. The front ejection shaft is assembled to the front supporting block. A sliding ejection shaft serves as the rear ejection shaft. The rear ejection shaft and the spring are assembled to the rear supporting block. The front supporting block and the rear supporting block are fixed to the pressing bar through the two fixing screws. The rear ejection shaft is pulled backwards to stress the spring, the space between the front supporting block and the rear supporting block is enlarged, and the multiple diamond compacts can be loaded between the front ejection shaft and the rear ejection shaft. The device is easy to manufacture, convenient to operate and high in diamond compact grinding precision; and meanwhile, the production benefits can be increased, and the worker labor intensity is relieved.