Background: Fangcang hospital (cabin hospitals) played a key role in isolation and control of the infection sources during COVID-19 epidemic. The patients at Fangcang hospitals were complicated, and many had different symptoms of COVID-19, some had comorbidities or mental stress, and many were confused with the drug usages etc. Objective: Due to the limitation and high work pressure of first line medical workers, patients’ various problems couldn’t be explained well. Under this circumstance, online pharmaceutical care was provided by clinical pharmacists. This study was a retrospective study to evaluate the role and usefulness of clinical pharmacists at Jianghan Fangcang Hospital. Besides, this new mode of service was also introduced in detail to provide options for pharmacists in other hospitals. Methods: The pharmaceutical care included medication education via broadcast station, and medication reconciliation, optimization of drug use, monitor of adverse drug events, and psychological comfort via WeChat® one-to-one service. In this study, we analyzed patients’ characteristics and drug usages, concluded almost 200 patients’ problems classified into 6 aspects solved by clinical pharmacists, and also assessed the patients’ satisfaction with our service. Results: The clinical pharmacist help patients solved almost 200 questions, which mainly focused on the drug related problems including drug usage (65.38%), medication reconciliation (55.13%), drug precautions (23.1%), adverse drug reactions (35.9%), and psychological counseling (32.05%). Through 35 days’ services, Most patients were satisfied with clinical pharmacist service(66.7%great, 18.0%good). Besides, most patients thought the service had positive effect on their mental stress(16.7%great, 43.6%good, 26.9%fair). Conclusion: The results of the retrospective study indicated that clinical pharmacist can effectively reduce and prevent drug-related, life-related and COVID-19-related problems for COVID-19 patients. This work may provide possible work patterns for clinical pharmacist in other hospital and give more professional service for Fangcang hospital patients.