Objective To establish a COM-B model based mobile health platform for patients with heart failure（HF）, and to evaluate its effect on self-management. Methods A mobile health platform for HF patients, which consists 4 modules of health information, self-management feedback, nurse-patient communication, and outpatient follow-up, was constructed through literature review and expert consultation. A total of 207 HF patients admitted to the department of cardiology were randomized into 2 groups. The control group （n=102） was subjected to standard hospital care, while the the intervention group （n=105） additionally joined a 6-month program with the help of the mobile health platform. The HF knowledge, self-care ability and medication compliance of the two groups were evaluated after 6 months. Results There were significant differences in before-after scores of the HF knowledge, self-care ability and medication compliance in the intervention group, whose scores were also significantly higher than the control group（P＜0.01 for all）. Conclusion The mobile health platform based on COM-B model can improve the knowledge level, self-care ability and medication compliance of HF patients. The platform enables convenient, effective and low-cost transitional care to the patients.