In order to study the influence of switching tube drive circuit, power transformer, output filter inductor and other parameters on the working state and technical indicators of half-bridge converter, an open-loop circuit model of half-bridge converter is established based on power simulation software Saber. The calculation method of key parameters such as power transformer and output filter inductor is given in half-bridge converter. The steady state of the half-bridge converter is analyzed by piecewise linear analysis, small ripple approximation analysis and volt-second equilibrium condition, and the output and input functions of the output filter inductor under continuous conduction mode (CCM) and discontinuous conduction mode (DCM) are derived. The critical values of output inductance, load resistance and duty cycle of CCM half-bridge converter are analyzed. The open-loop model of the half-bridge converter is simulated, and the simulation results verify the correctness of the theoretical derivation. Based on this, the parameter design method to improve the steady-state performance and working efficiency of the half-bridge converter is given, which provides a theoretical basis for the design of the half-bridge converter.