With the implementation of the new investment management requirements, the power grid needs to make annual arrangements for investment planning under the premise of meeting the financial accounting constraints. However, the accounting situations of different investment and construction projects are with uncertainties, which intensifies the challenge of meeting the financial accounting constraints. The traditional annual planning and decision-making method for power systems does not take into account the requirements of financial accounting and ignores the randomness of accounting, making it difficult to support precise investment in the power grid. Therefore, a decision-making method for the annual planning of power grids taking into account the constraints of financial accounting is proposed. Firstly, an annual planning decision-making model for the power grid is established with the goal of minimizing the comprehensive cost during the planning period. Then, considering the uncertainty of financial entries during the planning process, model the chance constraints of financial entry requirements. Secondly, in order to facilitate the solution of the planning model, an analytical transformation method for the chance constraints of financial accounting is proposed. Finally, based on the Garver""s 6 and HRP-38 test systems and the actual provincial system in China, the effectiveness of this method in meeting the requirements of financial accounting is verified. The proposed model is conducive to achieving precise investment in power grid projects.