Abstract: In large-scale wind and solar base projects, the allocation of electrochemical energy storage and CSP molten salt energy storage can better absorb the photovoltaic curtailment on the project, but how to couple and optimize consumption and how to measure the investment income of the project directly affects the project establishment and investment decision. By establishing a binary energy storage coupling absorption model, the binary energy storage mode is calculated to absorb photovoltaic curtailment under different coupling modes, and the internal rate of return of project capital under the electrochemical energy storage integrated configuration mode, sharing mode and zero income mode are compared and analyzed, and the optimization strategy of photovoltaic curtailment in dual energy storage coupling absorption project is proposed, which provides a feasible idea for project establishment and investment decisions of similar large-scale wind and solar base projects.