Abstract: This paper proposes a three-layer optimization model to address how grid companies can effectively incentivize load aggregators and end-users to participate in power demand response under cost constraints. By analyzing the cost-benefit relationships among grid companies, load aggregators, and users, value functions were established for each party to construct a three-tier optimization framework with load aggregators as intermediaries. An algorithm prioritizing grid company profit maximization was developed to solve the model. Experimental results demonstrate that the proposed approach ensures economic benefits for all participants, promotes energy conservation and emissions reduction, and reduces operational costs for grid companies within limited budgets, proving its theoretical and practical significance.