Based on the multiconfiguration Dirac-Fock method and impulse approximation, the electron capture and following radiation decay of the projectile ion are studied theoretically for Xe atom which is bombarded by Xe54+ ion at 197 MeV/u. The radiative electron capture (REC) cross-sections and the corresponding emitted photon energies have been calculated in detail. Meanwhile, the probabilities of the radiative decay and energies of the REC final states are also calculated; combined with the calculated results in this paper, the X-ray spectra structure of radiative decay from projectile ion is further simulated. It is found that the simulated spectra are in good agreement with the newly measured results at Lanzhou Heavy-Ion Accelerator Device.