The anti-reflection coating is researched theoretically based on the principle of the amorphous silicon solar cell. Following the quarter-wavelength action principle, the optimized thickness parameters can be obtained by computing the minimal reflectivity of the anti-reflection coatings. The single-layer anti-reflection coating adopts ITO(n=2.0, d=75 nm) with the weighted average reflectance of 5.91%; the double-layer anti-reflection coating uses MgF2/ITO with the thickness of 111 nm and 75 nm, and the weighted average reflectance of 3.72%. In addition, the variation curve of reflectivity with the wavelength is put forward to explain how to select materials according to the results calculated by the computer program: as for single-layer anti-reflection coatings, the materials with a small refractive index can achieve good results, and for the double-layer anti-reflection coatings, the materials with the low(up)/high(down) form of refractive index can get better effect.