In this study, magnesium hydroxide with thickness less than 10 nm were coated on the surface of ZnO tussock like nanorods by in situ electrochemical multi-potential pulse deposition. With the post-annealing temperature increasing, the nano overlayer on the surface of ZnO tussock-like nanorods undergoes phase transition from amorphous Mg(OH)(2) to amorphous MgO particles, and finally a ZnxMg1-xO solid solution layer with high crystallinity forms. With the changing of the surface overlayer on ZnO nanorod, the energy band potential of the corresponding photoanodes showed gradual negative shift and the charge mobility were also improved. The test results showed that the photoelectrochemical anti-corrosion performance of the modified ZnO tussock-like nanorods was significantly improved than that of pure ZnO tussock-like nanorods and the ZnO nanorod coated with ZnxMg1-xO soild solution nano overlayer showed greatly enhanced stability for photoelectrochemical anti-corrosion. Therefore, ZnxMg1-xO solid solution is considered as a dual-function overlayer for ZnO photoanode.