With the increasing maturity of big data technology, data as an objective indicator of hospital decision-making, its effective application has been paid more and more attention. Data quality will affect the accuracy, pertinence and effectiveness of hospital decision-making. Based on the quality and evaluation of medical data, the authors analyzed the problems existing in data quality, and put forward countermeasures to improve data quality, including improving management system to improve data integrity and standardization, establishing statistical platform system to improve data consistency, establishing data center to improve data integration and governance ability.