In order to improve corrosion resistance of the SiC_p/ Al composite material, it was treated by electroless Ni plating firstly and then the rare earth coatings were deposited on the surface of it . The effects of the Ce( NO₃)₃concentration of rare earth solution and deposition time on the corrosion resistance of Ni-P coating were discussed. The results show that: Putting the sample into 1 g / L rare earth solution for two hours at room temperature, prepared using the formula, then generate the Nimultilayer corrosion films of rare earth which show the best corrosion resistance. The corrosion potential of the film is-0 . 48 mV, corrosion current density is 3 . 54 X10^-8A / cm². In the films of rare earth Ce-oxides is in the state of oxide particles which accumulate together, the Ce-oxides particles play a key role in sealing process. Ni-P alloy is found in polycrystalline, while due to rare earth is a little in the coatings, none peaks in the XRD. The higher concentration of rare earth, the faster of deposition is,at the same concentration, the thickness increases with time, the greater the thickness of the film, the worse of the adhesion.