Abstract: In this paper, a nano-scale metal（silver） grid coating was proposed for the photovoltaic/thermal applications（PV/T）, it has high transmittance in the solar radiation band（0.3-2.5 μm）, and high reflectivity in the infrared band（2.5-25 μm）. When combined with PV/T absorber with high absorption/emission in the full band（0.3-25 μm）, it can guarantee the spectral selection characteristics of high absorptivity in solar band and low emissivity in infrared band, which can significantly reduce the radiation heat loss of PV/T. Based on the finite-difference time domain method, the effects of grid period, width and height on the spectral characteristics of metal grid coatings were simulated and analyzed. The results show that when the period of the nano-metal grid is 500nm, the height is 50 nm, and the width is 30 nm, the transmittance in the solar band reaches 0.90, and the mid-infrared reflectance reaches 0.88. Compared with the existing ITO coating, the solar radiation transmittance of the metal mesh coating is increased by 20%, the infrared reflectance is increased by 24%, and the sheet resistance（5.3 Ω/Sq） is reduced by 47%.