In order to simplify the structure of the active frequency selective surface (FSS) and improve the control performance of its resonant frequency, we propose an optically controlled active FSS that uses the photoconductive properties of the photoconductive thin film to change the structure size of the FSS. The relationship between the structure size of FSS and the center resonant frequency is elaborated in theory. Taking the optically controlled active FSS of cross dipole slot-element as an example, the center resonance frequency is changed from 23 GHz (before illumination) to 28 GHz (after illumination)by software CST simulation. The optically controlled active FSS structure is fabricated by coating, electron beam evaporation and photolithography. The influence of the doping amount, annealing temperature, annealing time, light frequency and light power on the photoelectric properties of the photoconductive thin films is analyzed. The results show that the sensitivity wavelength changes with the molecular number ratio of CdS and CdSe (1∶1~5∶1); the molar molecular number of CdCl2、InCl3 and CuCl2 could change the ratio of bright square resistance and dark square resistance, and the effect is best when the molecular number ratio is 3.6∶2.6∶1.3; with annealing temperature of 750 ℃ and annealing time of 30 s, the photoelectric characteristics and ohmic contact of photoconductive thin film reach peak. The test results show that the center resonance frequency of optically controlled active FSS is changed from 23.8 GHz to 28 GHz before and after illumination in the conditions of 200 mW/cm 2 light power and 0.6 μm light wavelength, which is consistent with the simulation results.