Based on the semiconductor photoconductive effect, the mechanism of photo-induced conductive composite mesh was analyzed, and the design ideas and structural characteristics of the photo-induced conductive composite mesh were clarified. Combined with the transparent sapphire substrate, the radar wave 2~18 GHz and infrared 3~12 μm wavebands were selected as the research object to optimize and simulate the parameters of the composite mesh structure. When the period of mesh parameter cycle changes from 5 mm to 2.5 mm, and the side length changes from 4.9 mm to 2.4 mm , correspondingly, the central resonance frequency of the mesh changes from 13.2 GHz to 14 GHz. The principle of coaxial alignment of diffraction gratings was used to ensure the alignment accuracy of the two lift-off lithography processes. The mesh cycle error is less than 6 μm and the length error is less than 5 μm, which satisfies the experimental requirements. The optical and electrical properties of the composite mesh were tested, and the results are: compared the sample without sapphire substrate with the composite mesh, the overall trend of the infrared transmittance curve did not change, and the overall transmittance decreased by about 7.8%, which is a 3.4% difference from the single metal mesh. This is in line with the law of infrared transmission loss. The central resonant frequency of the composite mesh measured at a sensitive wavelength of 600 nm is changed from 13.22 GHz to 14.03 GHz, which is basically consistent with the simulation results. Thus, the feasibility of illumination to control the electromagnetic performance of the composite grid was verified.