Aiming at the fact that more and more carbon emission trading (CET) is included in the industry, an energy storage capacity planning model considering carbon emission trading is proposed. First, analyze the CET trading rules, and establish a carbon emission trading model that maximizes the profit of each power generation entity. Secondly, according to the construction cost and service life, the energy storage cost model allocated to the unit energy is established, and the maximum marginal benefit of the system is used as the objective function to optimize the energy storage capacity. Finally, energy storage is configured in an industrial park in the south. Through the analysis of energy storage capacity allocation in the CET market environment, the effectiveness of the model is verified from two aspects of economic and environmental benefits.