Abstract: With the rapid development of radio astronomy research, the requirements to the sensitivity and resolution of telescopes, as well as wider observing band, constantly grow.The low frequency receivers are usually installed at the primary focus of the telescope so that the feed horns are smaller and lighter. The switching system of prime focus receivers must be effective and compact to avoid affecting normal use of the receivers on the secondary focus. A steerable 100m aperture radio telescope is supposed to be built in Qitai, Xinjiang (QiTai radio Telescope, QTT).This paper introduces a new solution of the switching system for the QTT primary focus receivers by using a linear module. Through the modeling and simulation of this scheme, and analyzing of the aperture interception to the observing signals, it is shown that our design well satisfies the efficiency requirement of QTT.