Abstract: The rapid development of the polarization converter puts forward the urgent need for the corresponding test system. In this paper, a polarization converter test system based on arch-method is proposed. The composition and principle of the test system are introduced and the time domain and the error processing of the test results is carried out by using the method of time-domain, frequency-domain interconversion and time-domain window.At the same time, a set of VB.NET-based control software is developed and a polarization converter based on metasurface structure is researched for comparision and verification. Through the comparison of simulation and test, the reflectivity test error of the proposed test system is expected to be better than 2 dB, and its test efficiency is improved by more than 80% compared with traditional mechanical methods. The developed test system is expected to become an advanced development case in this field, and promote the scientific research and engineering implementation of polarization converter test technology.