Objective: The paper explores the accounting system of medical insurance fund suitable for China's national conditions, to promote the reform of medical insurance management system. Methods: From the perspective of accounting theory, the theoretical basis of the accounting entity assumption of medical insurance fund and the fundamental role of the accounting entity assumption were discussed, and the conflict between the current single fund accounting entity and the administrative management system in China was analyzed from the perspective of accounting practice. This paper analyzes the feasibility of the dual accounting entity model of "fund plus units" in a way that combines theory and practice. Conclusion: A fund accounting system suitable for the management of medical insurance funds in China should be established to provide institutional guarantee for promoting the reform of medical insurance management system and improving the efficiency of medical insurance fund use. Suggestion: The dual accounting entity model of "fund plus unit" should be adopted to establish the accounting entity of the medical insurance fund, so as to achieve the accounting objectives of improving the decision-making quality of the management entity, relieving the public fiduciary responsibility, improving the efficiency of fund use, and reducing the risk of fund misappropriation.