Although heart failure (HF) symptoms affect patients' quality of life (QoL), improving patients' QoL requires certain self-care behaviours. However, the specific role of self-care behaviours in the relationship between HF symptoms and QoL has not been clarified. To evaluate the status of symptom clusters, self-care behaviours and QoL in HF patients, and to analyse and test the moderating effect of self-care behaviours between symptom clusters and QoL. This study is a cross-sectional study. A total of 320 HF patients who treated in thethree hospitals in Chengdu, China, from December 2022 to July 2023 were selected as the research subjects. The patients were evaluated using The General Information Questionnaire, Memorial Symptom Assessment Scale Heart Failure, Self-Care of Heart Failure Index and Minnesota Living with Heart Failure Questionnaire. The statistical analysis methods were exploratory factor analysis, Pearson correlation analysis, hierarchical regression analysis and simple slope analysis. There were five symptom clusters in HF patients: emotional symptom cluster (sadness, anxiety, irritability, feeling nervous), digestive symptom cluster (lack of appetite, dry mouth, weight loss, nausea, abdominal distension), ischemic symptom cluster (dizziness, chest pain, palpitations, fatigue), dyspnoea symptom cluster (difficulty breathing when lying flat, waking up breathless at night, sleep difficulty) and congestion symptom cluster (cough, shortness of breath, oedema). There was a significant correlation between HF symptom group, self-care behaviours and QoL (p < 0.05). Both self-care maintenance (β = -0.262, p < 0.001) and self-care management (β = -0.258, p < 0.001) had a moderating effect between symptom clusters and QoL. There are a variety of symptom clusters in HF patients. Improving the self-care behaviours ability of HF patients is conducive to reducing the impact of HF symptom clusters on QoL. The study used the STROBE checklist for reporting. Medical staff should focus on the impact of HF symptom clusters and self-care behaviours on QoL, and formulate corresponding interventions for HF symptom clusters and self-care behaviours to improve the QoL of patients. The head nurse of the cardiovascular department actively assisted us in collecting questionnaires from HF patients, and all HF patients surveyed participated in this study seriously.