A soft template method was used to prepare mesoporous silica with ethyl orthosilicate (TEOS) as the silicon source and cetyltrimethyl ammonium p-toluenesulfonate (CTATos) as the template agent. Triethanolamine (TEOA) and ammonia were selected as the alkali source separately and adjusting the ratio of ethanol and water. The results show that the optimal reaction conditions for the prepared nano-sized mesoporous silica include TEOS 1.56 mL, CTATos 1.92 g, TEOA 1.9 mL, ethanol 10.5 mL and water 74.5 mL; the optimal reaction conditions for the prepared submicron-sized mesoporous silica include TEOS 1.56 mL, CTATos 1.92 g, ammonia 1.9 mL, ethanol 42 mL and water 43.5 mL. The grafting method was used to functionally modify mesoporous silica by using azobenzene derivatives as modification materials. The test results were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectrophotometer (UV-vis) and thermogravimetric analyzer (TGA). The results show that the particle size of the prepared mesoporous silica is controllable and uniform with good dispersibility; and the modified mesoporous silica has photo-responsive properties.