The residual stress induced by Laser shock processing (LSP) can improve properties of fatigue crack growth. In this paper, the CT models of LSP and fatigue crack growth have been built. We experimented the TC4 alloy treated by LSP and fatigue crack growth and then simulated the fatigue crack growth. The results show that the values of simulations are conform to experiments. With the increment of peak pressures and overlapping rates, the fatigue lives have been increased, the fatigue crack growth rates have been descent. The fatigue lives have been 1.46-3.03 times compared with untreated by LSP, the fatigue crack growth rates have been 0.127-0.95 time compared with untreated by LSP, but to overlapping rates, it is not obvious with the improvement compared with peak pressures.