The utility model discloses a constant -temperature lead screw, bearing frame and evaporimeter including two same sizes, be equipped with the lead screw through the bearing housing between the bearing frame of two same sizes, infrared temperature sensors is located the upper end of bearing frame, the collection room is located keeps away from the bearing frame one side of cup jointing the lead screw, collect the back flow that one side is fixed and the collection room communicates of room, the one end of back flow extends to the intracavity of lead screw, the other end fixedly connected with condenser of back flow, it is the cryogenic compressor of condenser that the condenser passes through condenser pipe fixedly connected with, the evaporating pipe that is close to collection room one end passes the collection room and extends to in the back flow, keep away from the evaporating pipe and compressor fixed connection of collecting room one end, be provided with the temperature sensor who is connected with the controller electricity on the controller, the controller passes through power line and infrared temperature sensors's interface connection. This constant -temperature lead screw, compressor can make the silk keep thick stick constant temperature rapidly, improve the machining precision and the work efficiency of lead screw.