A polar axis calibration system (100) comprises: a polar scope (10), a polar axis calibration control device (20) and a display device (30). The polar scope comprises an optical lens (11) and an image sensor (12) for collecting constellation images (IM); the polar axis calibration control device receives the constellation images from the polar scope and determines the position (P1) of the rotation center of the polar axis and the celestial pole position (P2), the position of the rotation center of the polar axis means the position of the rotation center (R0) of the polar axis (510) of the equatorial instrument in the plane of the constellation image, and the celestial pole position means the position of the celestial pole in the plane of the constellation image; and the display device is coupled to the polar axis calibration control device and used to display the constellation image, the celestial pole position and the position of the rotation center of the polar axis. The present invention also provides a polar scope, a polar axis calibration control device, as well as an equatorial instrument (500) and an astronomical telescope comprising the aforesaid polar scope or polar axis calibration system. According to the present disclosure, it is possible to align the celestial pole position directly with the rotation center of the polar axis, thus improving the calibration accuracy. Furthermore, it is possible to lower the requirements for the installation accuracy of the polar scope.