45° near-infrared dichroic beam splitter, with the spectrum 1530 nm transmitted and 1560 nm reflected, is designed and fabricated. Ta2O5 and SiO2 are selected as high and low refractive index materials. The structure of multiple cavity Fabry-Perot filter with 4H spacer is used to reduce the transitional region between transmittance and reflectance wavelength. The materials are evaporated by ion-assisted electron beam deposition, and optical monitoring method is used to control the thickness of each layer. The spectrum of the dichroic beam splitter is measured by spectrophotometer. The result shows that the optical energy transfer efficiency is higher than 92%, and the dichroic beam splitter is suitable for space laser communication system to separate different wavelength efficiently.