The Coulomb barrier and electron screening cause difficulties in directly measuring nuclear reaction cross sections of charged particles at astrophysical energies. The Trojan-horse method （THM） has been introduced to solve the difficulties as a powerful indirect tool. In order to understand experimentM spectra better, Geant4 is employed to simulate the method. Validity and reliability of simulation data are examined by comparing the experimental data with simulated results. The Geant4 simulation of THM future related experiments. improves data analysis and is beneficial to the design for
