Deposition rate is one of the important technical parameters of producing optical thin film by e-beam. Deposition rate affects the microstructure and chemical composition of film, which affects the optical and mechanical properties of film greatly. SiO2 material is one of the important low refractive index materials for producing optical film. Because SiO2 has a low thermal conductivity and sublimes when evaporated, some pits may emerge on the surface of material during evaporation. The pits may affect the evaporation characteristics of SiO2, which is disadvantaged to the stability of deposition rate. Considering the special evaporation characteristics of SiO2, the experiment of deposition rate control of SiO2 by e-beam auto-sweeping is performed. The experiment uses the designed sweeping controller to control the evaporation spot moves on the surface of material through a designed sweeping path automatically. During sweeping, the deposition control is performed by the PID closed-loop control. The result of experiment shows that good surface characteristics of material and stable deposition rate.