High cycle fatigue is one of the main failures of aero-engine. The improvement of HCF properties by laser shock processing (LSP) with multiple impacts is researched. Vibration fatigue tests of different 1Cr11Ni2W2MoV stainless steel samples are conducted at room temperature. X-ray diffractometry (XRD), scanning electron microscopy (SEM) and metallography microscope are used to investigate the influence on microstructure and mechanical performances with different impacts. The results show that with the laser impact times increasing, the residual stress and the roughness increase, while the depth of microstructure refining layer doesn′t change. The surface compressive residual stress is driven to saturation and the saturation value is up to -100%σ0.2. The depth of compressive stress has a wider increase with the impact times increaseing. Vibration tests show that the fatigue properties improve with the impact times increasing. By the superimposed effect of shock waves in multi-impact processing, the shock wave can translate into deeper materials, which make a great contribution to the greater depth of compressive residual stress and deformation microstructure, and to the further improvement of fatigue properties with multiple impacts at room temperature.