Abstract: OBJECTIVE To improve the medication safety of modern outpatient pharmacy. METHODS The DMAIC model of Six Sigma quality management system was used to analyze the medication safety of outpatient pharmacy in five steps:definition, measurement, analysis, improvement and control. The main reasons that influence the safety of medication were found out, and corresponding improvement measures were made to reduce the safety factors of medication. RESULTS Error rates decreased from 0.064% to 0.008 5%, the difference before and after improvement was statistically significant (P<0.05). CONCLUSION In hospital management, applying Six Sigma through teamwork, using data to talk about the key factors of the problem, eliminating process defects and implementing process improvement are effective ways to improve medication safety.