 This study proposes a two-layer game model to optimize the day-ahead power market. It considers the interactions between the power grid, sales companies and users and analyzes their respective objectives. The model is then optimized using a multi-objective, multi-universe algorithm to determine the best strategies for all parties involved. This approach can help maximize the overall benefits of the day-ahead power market, including the profits of the sales companies, the costs of the consumers and the comfort level of the users. This article was authored by Guinyin Hu and Tao Wang.