Purpose/Significance The data security management system is built based on the big data of medical alliance to achieve the purpose of enhancing data protection, reducing security risks and improving data security. Method/Process By analyzing the business scenario of medical alliance, data security policies and application security technologies are established in the full life cycle of collection, transmission, storage, processing, sharing and destruction, and the construction of data security system is improved. Result/Conclusion The data security management system is a “safety belt” for the business of medical alliance. With a clear security system and standards as the outline, it provides an effective path for the legal and compliant development of hospital business and establishes a feedback mechanism.