Based on the energy balance, the energy equations of the furnace gas, furnace wall, radiant tube surface and strip surface were established by the ternary method for radiation tube furnace (RTF) of process section of the continuous hot-dip galvanizing line, and the energy exchange between the model sections was shielded to achieve the effect of accelerating calculation and the dynamic adjustment need was satisfied. According to the internal heat conduction equation of thick strip steel, the internal temperature field of the strip and the temperature field in the furnace were obtained by the finite-difference method, which was consistent with the on-site detection value. The correctness of the model was verified. Under the assumption of pursuing the highest production efficiency, offline simulation results of an optimized process parameters were achieved. As a result, when the thickness of the incoming strip was 2 mm, the matching running speed reached the speed limit value of the conveyor of 200 m/s. The first heating section opened the maximum fuel flow rate of 255~260 L/min. The second section increased the product temperature while reducing the cross-section temperature difference and improved fuel utilization by reducing the flow rate. 2 mm strip steel corresponding minimum temperature difference was 0.18℃, fuel flow reduced to 174 L/min, corresponding minimum unit energy consumption was 1049 L/t. The maximum temperature difference of 5 mm strip was 0.60℃, the second section fuel flow was 230 L/min, corresponding maximum unit energy consumption was 1071 L/t. Reasonable determination of process parameters was conducive to heating the strip and improving the overall production efficiency.