Abstract: Based on the random fluctuation of new energy sources and the low conversion efficiency of the low-temperature electrolytic hydrogen production system and the inability to switch to the power generation state,an efficient multi model optimal control method for maximum hydrogen production points under the variable load condition of high-temperature electrolytic hydrogen production is proposed.Firstly,a multi-energy coupling optimization model for the overall coordinated operation of the high-temperature solid oxide electrolysis system including auxiliary equipment is constructed,and many factors affecting the working temperature,current intensity,material flow rate and other factors of the system electrolysis are analyzed,and the high-energy safe hydrogen production rate is derived. Secondly,on the basis of PID control,an adaptive time-varying linear variable parameter model predictive control method is proposed,which can not only realize synchronous and accurate tracking of hydrogen production trajectory and optimize the power grid regulation demand,but also maximize the hydrogen production efficiency. Finally,an example is given to verify that the proposed method has faster temperature rise rate and shorter transition time than the PID control electrolysis system,and the electrolysis current,steam flow rate,hydrogen flow rate and electric furnace power can all smoothly transition to the steady point,which has certain theoretical and practical value.