Abstract: In order to study residual stress distribution characteristics of TC17 dual phase titanium alloy by one-side and two-side laser shock peening (LSP), numerical simulation was taken to analyze the residual stress distribution rules under one-side and two-side LSP.The results show that after the stabilization of one-side impact, tensile stress is generated on the opposite surface of the impact and compressive stress is generated on the impact surface.For two-side simultaneous LSP, part of the residual compressive stress is used to offset the tensile stress, and the superposition and weakening of the stress wave leads to the reduction of the residual stress level at the same time.The maximum residual stress in the x direction and y direction obtained by one-side LSP is 336.709MPa and 337.011MPa, while it is 326.401MPa for two-side simultaneous LSP in both directions.One-side LSP is unfavorable for suppressing the crack due to the caused tensile stress.The residual stress distribution on both sides of the specimen is almost the same for two-side simultaneous LSP.The residual stress of the first impact surface is higher than that of the second impact surface after two-side successive LSP.The influence of transverse propagation of shock wave on residual stress should be considered for finite specimens.The result would be a certain guidance for study on residual stress distribution rules by one-side and two-side LSP.