With the continuous access of distributed PV to the distribution network and the phenomenon of “curtailment of hydro”, in order to absorb the PV and make full use of it, the excess PV can be absorbed through the IES. In order to plan and size the comprehensive energy system economically and reasonably, firstly, the interaction model of multiple energy flow source-charge in the system is modeled, and the interaction nodes between energy flows are defined. Then, considering the objectives of cost and benefit, unit equipment involved in IES planning are constrained and the optimization strategy is selected. Finally, validated the rationality of the optimization model of the IES proposed in this paper is verified by the example of the integrated energy application scenario set up for the specific absorption of photovoltaic energy, which reflects the effectiveness of the IES for the cross-border absorption of photovoltaic energy.