To achieve an optimized laser-assisted ultra-precision cutting process for monocrystalline silicon and to explore the surface characteristics of monocrystalline silicon components after cutting， the in-situ laser-assisted single-point diamond cutting process parameters of monocrystalline silicon are optimized by the orthogonal experimental method. Various parameters of monocrystalline silicon are measured and analyzed， such as surface quality and accuracy， residual stress， and optical transmittance. Through the variance analysis of the surface roughness and signal-to-noise ratio analysis of the orthogonal experimental data， the optimized process parameters are obtained as follows： spindle speed=1 500 r/min， feed rate=5 mm/min， cutting depth=3 μm， and laser power=4.5 W. The surface roughness and accuracy PV are 2.74 nm and 0.52 μm， respectively， for the 165 mm monocrystalline silicon aspheric optical lens processed with the above process parameters. After the laser-assisted cutting， there is residual stress of （-1 760.8±362.1） MPa on the monocrystalline silicon. The machined monocrystalline silicon's refractive index is 3.43， and the transmittance before and after the coating is 55% and 98%， respectively， in the common 3–5 μm mid-infrared band. The above research results show that laser-assisted ultra-precision machining technology can be used as the semi or final finishing process to improve the manufacturing efficiency of complex surface monocrystalline silicon lenses.