The work aims to improve corrosion resistance of NdFeB magnets. Composite Zn coating containing SiO2 and TiO2 nanoparticles were electrodeposited on the surface of NdFeB magnets. Composite Zn coating with 3 wt% SiO2 nanoparticles were obtained by adding 10 g/L SiO2 nanoparticles in chloride zinc galvanizing solution solution, and only 0.3 wt% TiO2 nanoparticles were present in composite coating by adding 10 g/L TiO2 nanoparticles in plating solution. According to neutral salt-spray corrosion and saline soak corrosion tests, the corrosion resistance of SiO2-Zn composite coating is improved significantly while the TiO2-Zn composite coating is not. After being further preserved and continuously used for one year, the composite plating solution containing nanoparticles can still keep excellent homodisperse stability of nanoparticles and the characteristic of precipitating SiO2 nanoparticles in the coating.