Abstract: With the rapid development of new energy and the continuous advancement of energy storage (ES) marketization, an independent energy storage day-ahead market bidding strategy considering conditional value-at-risk (CVaR) is proposed. This approach aims to address the risks arising from the uncertainties in new energy power generation and load on the energy storage market transactions, thereby ensuring the profitability of energy storage. Firstly, the framework is established for independent energy storage to participate in the day-ahead energy and frequency regulation markets. Secondly, a dual-layer optimization model for the day-ahead market bidding strategy is constructed. The upper layer aims to maximize the market revenue of ES operators, incorporating CVaR as a risk management method to meet the decision-making needs of ES operators with varying risk preferences. The lower layer aims to minimize power purchase cost for joint market clearing. Subsequently, the dual theory and the Karush-Kuhn-Tucker (KKT) optimality conditions are utilized to solve the model. Finally, the actual data from a certain region are used to verify the model with the improved IEEE 30-bus system, and the effectiveness and practicality of the proposed method are confirmed by simulation results.