The paraffin-based fuel is an ideal power for the solid-liquid hybrid-engine.The energy characteristics of paraffin-based fuel and HTPB fuel were calculated by minimum free energy method under more oxidizer, more fuel, and the optimal oxygen-fuel ratio working conditions.The regression rate of paraffin-based fuel and HTPB fuel were tested by rectangle solid-gas hybrid engine.The energy characteristics results show that:the fuel′s oxygen contents are increased by adding AP, but the optimal oxygen-fuel ratio and specific impulse are both reduced.The chamber temperature and density specific impulse are improved by adding Al, and the specific impulse of paraffin-based fuel and HTPB fuel are basically similar.The regression rate results show that:with the increasing oxidizer mass flow rate from 25 g·s^-1 to 40 g·s^-1, the regression rate of paraffin-based fuel is improved from 0.79 mm·s^-1 to 1.11 mm·s^-1, the regression rate of HTPB fuel is improved from 0.47 mm·s^-1 to 0.68 mm·s^-1; the regression rate of paraffin-based fuel is higher than that of the common HTPB fuel about 1.58-1.74 times.