Objective To provide direction for the improvement of quality control of hospital preparations and ensure the safety for clinical use by analyzing the hospital preparation deviations in recent three years. Methods A retrospective analysis on 59 minor hospital preparation deviations from 2017 to 2019 was conducted. Brainstorming, fishbone drawing and, Minitab software were used to analyze the root causes of deviations from five aspects: personnel, machine, materials, methods and environment. The preventive and corrective measures were implemented. The results were evaluated. Results 1 significant deviation (1.7%), 24 major deviation (40.7%), and 34 minor deviation (57.6%) were identified among the 59 casses of preparation deviation. With the implementation of preventive and corrective measures, the total number of deviations in 2018 was significantly reduced compared to that in 2017. The total number of deviations in 2019 was about the same as that in 2018. The human factors need to be focused. Conclusion The pharmaceutical preparation deviations in our hospital have been reduced. The further quality improvements for pharmaceutical preparations will be carried out by following the regulations of pharmaceutical production quality management standards and pharmaceutical production supervision and administration measures.