Silver nanoparticles are grown on the surface of TiO₂ nanorods by ultraviolet irradiation and used as surface-enhanced Raman scattering substrate. The effect of ultraviolet irradiation time on Raman sensitivity is studied, and samples of TiO₂ nanorods/silver composite structure are prepared under different irradiation time. COMSOL Multiphysics simulation software is used to calculate the electromagnetic distribution and theoretical enhancement factors on the surface of TiO₂ nanorods/silver composite structure. The experimental results show that the detection concentration of rhodamine is lower than 10 ^-10 mol/L and the maximum enhancement factor is about 1.84×10 ⁸ after 10 min of ultraviolet irradiation, indicating that the substrate has good self-cleaning function.