Abstract: User-side energy storage refers to energy storage equipment installed by power users. As a crucial component of new energy storage, it plays a significant role in ensuring the safety and stability of the power system, promoting the consumption of renewable energy, and building a new type of power system. The decentralized nature of user-side energy storage makes it difficult to fully understand the installation status of energy storage equipment. This not only affects the effective supervision of policies but also reduces the enthusiasm of user-side energy storage to participate in demand-side management. To address this issue, a method for identifying the installation of user-side energy storage equipment is constructed. By eliminating photovoltaic power output to restore users' real load data, the time-series classification algorithm based on Transformer is applied to the scenario of identifying the installation of user-side energy storage equipment for the first time. This realizes the accurate identification of installed and operational energy storage equipment, fills the gap in the technical application field, supports the smooth development of regulatory work on user-side energy storage equipment, promotes the optimization of demand-side management, prevents potential power grid safety risks and fluctuations, and responds to the national policy of strengthening the supervision and management of new energy storage grid connection and dispatching.