Objective To observe the effect of applying PDCA cycle method to promote the management of key monitoring drug, and provide a basis for the management of key monitoring drug in medical institutions. Methods To compare the consumption of drugs and prescription reviews before and after the adoption of PDCA management in a hospital. The control group was the inpatients with traditional management method in 2019, and the observation group was the inpatients with PDCA method in 2020. Results After the implementation of PDCA cycle, the consumption amount of key monitoring drugs decreased significantly (P<0.001); The problems of irrational prescription such as drug use without indication, repeated drug use, inappropriate dosage and route of administration, and long course of treatment were effectively controlled (P<0.05). The qualified rate of prescription increased from 65.96% to 90.76% (χ²=27.010, P<0.001). The incidence of adverse reactions was significantly decreased (χ² =37.044, P<0.001). Conclusion PDCA method aims at continuous closed-loop management of key monitoring drugs in medical institutions, which can control drug costs to the greatest extent, reduce the economic burden of patients, promote rational drug use, reduce the incidence of adverse reactions, and ensure the quality of medical care.