Two-sided laser shock processing (TSLSP) is often employed to improve the surface quality of thin section components, which can reduce excessive plastic deformation induced by one-sided laser shock processing. Residual stresses (RS) field induced in a thin Ti-6Al-4V alloy plate by TSLSP was investigated through numerical simulation. The multiple TSLSP impacts and the increasing laser shock pressure were found to have significant effects on the RS field. Microhardness distribution on the section of specimen, calculated from RS by Carlsson-Larsson model, is analyze