Laser shock processing or laser peening has become an advanced and promising surface treatment technique and has been shown to be effective in increasing the resistance of metallic components to resistance wear, resistance corrosion and high-cycle fatigue (HCF), etc., through high density dislocation and imparting compressive residual stress on the surface of a n mber of metals and alloys treated by nanosecond pulse high energy laser. The higher laser energy/power density could induce the higher density dislocation, deeper effect layer, larger action area and better treatment effect. The principle of LSP was presented and the improved pressure model was used to estimate shock pressure of plasma. Energy of about 30 J with infrared (1064 nm) radiation and frequency 1 Hz was used. The Nd:YAG laser with 15 ns pulse width was used in this work. The Nd:YAG laser with high energy was used to treat the 7050-T7451 alumin m alloy, which has been employed in the fatigue-critical aircraft components due to its high strength, good stress corrosion cracking property and high fracture toughness. The pulse laser is focused to a diameter of 6mm onto the Al alloy samples. The Al foil tape was used as absorbing layer. The laser system included laser with high energy, external optical path system, energy display system and motion control system. The fatigue performance was tested by hydraulic servo fatigue testing machine with the model of MTS-50kN-5. The dyn mic pressure could reach 100 kN and frequency 1Hz-100Hz. The objective of this work is to examine the effect of laser shock processing on the Al alloy hole structure. The microstructure treated by LSP was observed comparing with the non-treated samples. The fatigue properties of samples were improved after LSP.