In order to determine the material constitutive model parameters of FGH4095 alloy treated by laser shock processing (LSP), the Johnson–Cook (J-C) plasticity model was selected. The strain hardening function parameters A, B and n can be determined form true plastic strain-stress curve. In this work, the engineering stress–strain stress curve was obtained from China Superalloys Handbook, which was converted into a true strain-stress curve, and then the elastic part of this curve was removed to obtain the equivalent plastic stress–strain. Parameter A is the initial yield stress in true plastic stress–strain curve, parameter B and n were determined by least square method of f1(ɛ)=A+Bɛn in the true plastic stress–strain curve. For the determination of parameter C, a method based on LSP experiment and LSP numerical simulation was proposed. We assumed the initial predicted value of parameter C is 0.0015, and then the numerical simulation work was undertook with the change of predicted value of parameter C until the error of the maximum compressive residual stress obtained by experiment and simulation falling into allowable range (±1%), and then the parameter C was determined. At the end, the J-C plasticity model parameters of FGH4095 alloy with A = 1057 MPa, B = 1420 MPa, n = 0.3625 and C = 0.011 were determined, which has important reference value and guiding significance for researchers to carry out the LSP numerical simulation work. © 2020