Pulse field magnetization (PFM) for HTS bulk magnets has the advantage of a field cooling method, because it does not require a superconducting magnet. To reach the largest trapped magnetic field in the HTS bulk using the PFM method requires repeated applications of the pulse magnetic fields to the HTS bulk with controlled temperature and amplitude of the pulse magnetic field. We previously reported the influence of HTS bulk properties on the PFM method, and our numerical results corresponded with the experimental results when a single pulse magnetic field was applied. In this study, we applied multi pulse magnetic fields to the HTS bulk using this numerical model. The results show the outer and inner shielding currents in the HTS bulk exist in opposite directions, while the surface magnetic field is reduced by the magnetic field produced by the negative direction current. We suggest a new method to reduce the outer shielding current using a heater. Our numerical results demonstrate the possibility of increasing the peak of the trapped magnetic field in the heating method.