圆光斑激光冲击强化条件下由于冲击边界产生反向塑性加载效应，会产生“残余应力洞”现象。对TC17、1Cr11Ni2W2MoV、LY2和K417等4种材料进行圆光斑单点激光冲击试验，通过显微硬度和残余应力测试验证了“残余应力洞”的存在，并分析了激光功率密度和强化次数等参数对“残余应力洞”现象的影响。为了抑制“残余应力洞”对强化均匀性的影响，以TC17为对象，优化光斑搭接工艺并开展多遍强化试验，结果表明，与单个光斑强化相比，同样激光参数下，采用特殊光斑搭接和多遍强化可以有效抑制圆光斑残余应力洞现象，提高强化效果均匀性，残余应力和显微硬度平均值分别提高60 MPa和30 HV0.2，极值差分别降低了70 MPa和94 HV0.2。

In laser shock processing with circular laser spot, reverse plastic loading originating from the boundary of unaffected area will result in “residual stress hole” phenomenon. The “residual stress hole” phenomenon is proved by microhardness and residual stress test results of titanium alloy TC17, stainless steel 1Cr11Ni2W2MoV, aluminium alloy LY2 and Ni-based alloy K417 processed with single circular laser spot. Especially, the received effect laws of laser power density and impact times to “residual stress hole” phenomenon are studied. In order to reduce the influence of “residual stress hole” on the uniformity of strengthening, titanium alloy TC17 is chosen to study the optimized overlap rate and impact times. Results show that compared with single spot processing, with the same parameters, appropriate overlap rate and impact times could efficiently restrain the effect of “residual stress hole”. Particularly, with the overlap rate of 66% and impact times of three, the average value of microhardness and residual stress are increased by 60 MPa and 30 HV0.2, and the differences are reduced by 70 MPa and 94 HV0.2, respectively.