In view of various application scenarios of energy storage technology in power systems and the relationship among different stakeholders, a business model of third-party invested energy storage based on the concept of shared energy storage is proposed, and economic analysis method and optimization algorithm of energy storage power station under the business model are established. By comparing profits with the contract energy management and the two-part electricity price business model, the proposed business model has a better economy when the income sharing is reasonable. The impact of energy storage battery type and configuration capacity on the economics of energy storage power stations is further analyzed. The economy and effectiveness of the proposed business model are verified through the calculation case of Hangzhou power grid, which can promote the commercial process of the energy storage industry.