Abstract: The 1.6 GeV proton synchrotron proposed in the Chinese Spallation Neutron Source(CSNS) project is a high-intensity proton synchrotron. In the phase Ⅰ of the project, the injection energy is 70 MeV and beam power is aimed to 100 kW at 1.6 GeV with repetition frequency 25 Hz. The main design principle of the power supply system is described in the paper, and some considerations for close dipole magnet（B） and quadrupole magnet（Q） field tracking during beam acceleration period are also discussed.