In recent years, the surface nanocrystallization (SNC) technology has received extensive attentions in the field of metal material. The shot peening and surface mechanical rolling processing technology can form the gradient nanostructured (GNS) layer on the surface of metal. The material surface roughness is large generally. Therefore, the problem how to form the thick, smooth, flawless GNS layer is need to solve urgently. By means of the hybrid surface nanocrystallization (HSNC) method of both supersonic fine particles bombarding (SFPB) and surface mechanical rolling treatment (SMRT), a gradient nanostructured surface layer was formed on 2A14 aluminum alloy plate. The electrochemical corrosion behavior of the HSNC sample at the air of room temperature and low temperature liquid nitrogen was compared with that of the original sample in aqueous solution of 3.5%NaCl. The results showed that grain size increases from about 30 nm at the surface layer gradually to coarse grain size of the matrix when the sample was processed by HSNC. The total thickness of the plastic deformation layer is about 130 μm. The surface roughness R_a is about 0.6 μm with the surface microcrack disappeared. Compared to the original sample, the pitting corrosion resistance of the SFPB samples was not improved and the pitting corrosion resistance of the HSNC samples was improved. The self-corrosion potential and pitting corrosion potential increase respectively from -1.01228 and -0.29666 V in the original sample to -0.67445 and 0.026760 V at the air room temperature of the HSNC sample. The pitting corrosion resistance of the HSNC sample at the air of room temperature was the biggest. The analysis showed that the surface GNS grain, significant increase of the nanocrystal boundaries, the introduction of compressive residual stress and the decrease of surface roughness were beneficial to improve the pitting corrosion resistance.