Abstract: Cross sections of radiative electron capture, non-radiative electron capture and target K-shell ionization by 300\sim 500 MeV/u Ar¹⁸⁺, Kr³⁶⁺ and Xe⁵⁴⁺ ions in collisions with Ar, Kr and Xe atoms, were calculated by nonrelativistic dipole approximation, relativistic eikonal approximation, ECPSSR theory and the plane wave Born approximation, respectively. Combined with energy resolution of X-ray detectors and Doppler effect of transition spectra of the projectile ions, expected X-ray spectra of various collision systems, beam energies and different observation angles are produced for X-ray spectroscopy experiment on internal target of the Heavy Ion Research Facility at Lanzhou-Cooling Storage Ring(HIRFL-CSR). These expected spectra can help us to select and optimize experimental conditions such as collision system, beam energy, observation angle, type of detector, window and absorbing sheet of X-ray. In addition, these expected spectra can prevent weak reaction channels from overlap or disturbing with strong reaction channels and corresponding escape peaks. Therefore, accuracy of experimental data can be ensured, and utilization efficiency of beam is improved.