Abstract: To analyze the influence of deep and shallow cold treatment on the surface residual stress of 2A12 aluminum alloy thick plates, the residual stress of aluminum alloy thick plate was tested by nondestructive testing method, and the effects of the two processes of cryogenic treatment and shallow cooling treatment on the surface residual stress of 2A12 aluminum alloy thick plate were compared. The micro-effect mechanism of reducing surface residual stress by cold treatment was analyzed by transmission electron microscope. The results show that the surface residual stress of aluminum alloy samples treated with shallow cooling（-80 ℃×12 h） is 51.6% lower than that of aluminum alloy samples with out cooling treatment.The surface residual stress of aluminum alloy samples treated by cryogenic treatment（-196 ℃×12 h） is reduced by 20.3%compared with that of uncooled samples. The effect of shallow cooling treatment（-80 ℃×12 h） on the surface residual stress of aluminum alloy is more significant than that of cryogenic treatment（-196 ℃×12 h） in the same cryogenic time.