Objective This study aimed to develop an individual WeChat Mini Program to provide pharmaceutical care to better manage cancer pain patients and to evaluate its feasibility and the differences in analgesic efficacy, medication adherence and safety versus conventional pharmacy interventions. Methods In this parallel randomized clinical trial, 42 cancer pain patients were equally allocated into the experimental group and the control group. The experimental group received individualized pharmaceutical care based on the “Yao Nin You Wo” WeChat Mini Program, while the control group received conventional care during the 4-week period. Main outcomes contained pain scores, medication adherence, incidences and relief rates of breakthrough pain, and incidences of adverse events. Relief rates of pain were also calculated according to pain scores. Results At the beginning of intervention, none of the pain scores and medication adherence showed relevant differences between the two groups (all P > .05). After intervention, the experimental group had significantly lower pain scores compared to the control group ( P = .003). Breakthrough pain of both groups was alleviate; not only the incidence of breakthrough pain considerably was lower at 4 weeks than at baseline, but the relief rate of breakthrough in the experimental group was higher than that in the control group. Compared with the control group, the medication adherence rate of the experimental group was significantly improved ( P = .02). Types of adverse events that happened in experimental and groups were similar, but the total incidence of adverse events in the experimental group was lower than that in the control group. Conclusions WeChat Mini Program is a useful and facilitative tool with the potential to improve cancer pain self-management ability in discharged patients. In addition, pharmacists could play a key role through the Mini Program to connect with patients successfully by providing personalized pharmaceutical services.