The invention discloses a clay moisture extracting device. The clay moisture extracting device comprises a shell, an extraction tank, a piston, a pressure plate, an air cylinder, a liquid collecting bottle and a material collecting tank, wherein the piston is arranged in the extraction tank, the pressure plate is fixed at the bottom end of the piston through a connecting rod, a filter is arranged at the lower end of the pressure plate, a filter screen is arranged at the bottom in the extraction tank, and the material collecting tank is mounted at the lower end of the extraction tank; and an exhaust tube is connected to the top end of the extraction tank, a feeding pipe with a one-way valve and a liquid extracting pipe are connected to the side wall of the extraction tank, a slide joint is mounted on the liquid extracting pipe, a connecting plate is mounted at the lower end of the liquid extracting pipe, the lower end of the air cylinder is connected to the connecting plate, a liquid charging control valve and a docking device are respectively mounted at the lower end of the liquid extracting pipe, and the liquid collecting bottle is arranged below the docking device. The clay moisture extracting device has the advantages that the structure design is reasonable, and the whole extraction processes are finished in a vacuum environment, so that collected moisture is in a natural state, the evaporation of the moisture is reduced, the pollution is avoided, and the cost is low.