Abstract: Aiming at the technical indicators of the sub-reflector adjustment mechanism of the QiTai 110 m aperture fully movable radio Telescope (QTT), a sub-reflector adjustment mechanism based on the 6-UPS parallel robot is proposed in this paper. The virtual prototype modeling and the dynamic simulation for the sub-reflector adjustment mechanism are carried out by using the multi-rigid-body dynamics analysis software and the control simulation software respectively. Then, the maximum driving forces required by the motion joint of the sub-reflector adjustment mechanism when it moves from the original position to the specified position under the conditions of 0° and 90° elevation angle of the main reflector are obtained. Moreover, a finite element model of the sub-reflector adjustment mechanism of a large radio telescope is established. Modal analysis is carried out for the structure of the large radio telescope when it is in the original position, and the first six natural frequencies are obtained, which provides a theoretical reference for the engineering design.