Precision micrometric displacement actuator used under polar region low-temperature environment

The invention provides a precision micrometric displacement actuator used under a polar region low-temperature environment, and relates to the precision micrometric displacement actuator. The precision micrometric displacement actuator solves the problem a supporting and adjusting mechanism suitable for a large-scale segmented mirror telescope under the polar region low-temperature environment does not exist at present. A base plate is mounted in a shell, a rolling linear guide rail is mounted on the base plate, and a left end cap and a right end cap are arranged at the two ends of the shell in a covering mode respectively. A flexible shaft is mounted on a driving rod, a motor seat is mounted on the rolling linear guide rail, and a stepping motor is mounted on the motor seat. One end of a screw rod is connected with the stepping motor through an elastic coupler, a base is mounted on the base plate, and a sleeve is mounted in the base. A first nut is mounted at the left end of the driving rod, a second nut is mounted at the right end of the sleeve, and the other end of the screw rod is screwed on the second nut and the first nut. One end of the driving rod is inserted into the sleeve and is connected with the first nut, and the other end of the screw rod is connected with the flexible shaft. A shaft sleeve is arranged on the driving rod in a sleeved mode, and a pre-tightening spring is arranged on the driving rod in a sleeved mode and is compressed between the first nut and the shaft sleeve. The precision micrometric displacement actuator is used in the segmented mirror telescope.