The integrated reform of budget management is the first step for national finance entering into comprehensive digitalization relying on big data and "Internet plus" and other information means, and it is a historic leap in digital financial reform. However, at present, there are still problems in the financial management of central administrative institutions, such as mismatched emphasis on pre-accounting, "two sets of accounts", increased risk of reconciliation errors, and increased difficulty in reconciliation. Therefore, the reform of integrated budget management is imperative. Taking S Provincial Bureau as an example, to conduct an in-depth analysis of the policy practice was conducted to integrate budget management, the problems in financial management, and the impact of integrated budget management reform on unit financial management. Finally, optimization methods are proposed for financial management to promote the integration of budget management and financial management, ultimately promote the smooth completion of integrated budget management reform and improve the financial management level of central administrative institutions.