When the machine tool lead screw is running, the speed is very high and the change of direction is frequent, so the heat can not be released in time, which results in high temperature rise. As a slender rod, the lead screw is sensitive to the change of temperature. According to the law of thermal error of the lead screw, the selection method of the lead screw thermal expansion zero point was put forward, and the error compensation model was established. The compensation method of the thermal expansion zero point of the machine tool lead screw was studied, and the compensation process of the thermal expansion error of the lead screw was analyzed; the significance of the lead screw thermal expansion zero point to the error modeling was proved by the compensation experiment.