Objective:To strengthen the integration and sharing of medical data resources, provide high-quality and usable data for clinical researchers, and promote the medical data use in clinical research.Methods:According to the development and application goals of the medical big data platform, data from different major clinical information systems in our hospital are integrated and then cleaned, processed and analyzed, and finally aggregated into a unified platform and turned to valuable and usable data resources.Results:A medical big data platform for clinical research in our hospital has been developed. It has stored over 13.42 million patients′ clinical data of more than 50 million visits since 2004 in our hospital; an analysis-oriented common data model (CDM) for clinical research has been designed; clinical researchers can query and extract clinical data according to CDM; the standard clinical research data service mechanisms have been established.Conclusions:The medical big data platform in our hospital helps to provide usable data of good quality for high-level scientific research based on medical big data, and improve the efficiency and quality of clinical research; at the same time, it also provides a efficient way to manage and control clinical research data use while ensuring data security and regulatory compliance.