Objective To carry out data quality project in Shenzhen city to realize standardization of key medical statistical indicators of outpatient and emergency treatment and informatization of data collection.Methods System theory and control theory were used to standardize the data source and collection process of medical and health statistical indicators.Results The meaning, statistical caliber, statistical algorithm and operation scripts of 23 key medical and health statistical indicators of outpatient, emergency treatment were standardized. Through testing and verification, the standard document .Specifications for Data on Health and Medical Statistics was formulated and released. By means of informatization, the informatization of data collection, standardization of operation and homogeneity of results of public hospitals′ indicators in the city were realized.Conclusion Study and realization of data standard for key medical statistical indicators of outpatient and emergency treatment in Shenzhen ensured the consistency of statistical results between the hospital and the central platform and improved data quality.