Abstract: In the context of the strategic dual-carbon goal, an optimization model considering multi-coupling variables under different typical days and scenarios is proposed, aiming to cope with the continuous enhancement of the accommodation capability for new energy generation by the Inner Mongolia power system and improve the energy utilization rate of the wind-photovoltaic-thermal-storage (WPTS) investment in desert base environment. First, the optimization model of WPTS is established. Subsequently, a two-layer optimal model considering the internal load and the capacity demand of the capacity channel is constructed according to the coupling characteristics of investment capacity and load power demand. Finally, by conducting Matlab simulations and solving Cplex, the optimal capacity configuration of wind-photovolatic- thermal-storage is obtained by designing four operating scenarios corresponding to four deserts. Simulation results demonstrate that the planned WPTS system is capable of coordinating the operation of the power system with the requirements of internal and external load demands well taken into account, and the energy supply balance degree could be effectively improved.