Abstract: Laser-driven neutron sources have potential applications in many fields of science and technology due to ultrahigh neutron flux and ultrashort pulse duration. We simulated the generation of photonuclear neutrons in the full-physical process by use of several numerical simulation codes. At first, we used 1D radiation hydrodynamics code to simulate the process of ultraintense laser prepulse interacting with Cu target, acquiring the preplasma electrons density profile. Then we got hot electrons information by 3D PIC code to simulate ultraintense laser main pulse interacting with the preplasma. At last we acquired the yield, spectrum and angular spectrum of photonuclear neutrons when the hot electrons impinging with Cu target simulated by Monte Carlo code. The simulation results show that the photonuclear neutrons yield up to 1.2108/J can be obtained using ultraintense laser with intensity 1022 W/cm2 interacting with Cu cylinder target whose thickness and diameter are 4 cm.