Abstract: Objective To investigate the composition of symptom clusters in early postoperative breast cancer patients and analyze the sentinel symptoms of each cluster of symptoms.Methods A total of 309 patients who underwent mastectomy were conveniently sampled and surveyed using the Chinese version of the Anderson Symptom Inventory. Principal component analysis and varimax orthogonal rotation were employed to analyze the symptom clusters, and their associations were analyzed using the Apriori algorithm model to identify the sentinel symptoms of each cluster of symptoms. Results Three symptom clusters were identified in early postoperative breast cancer patients: neuro-sleep symptom cluster fatigue (weakness)-distress-pain-sleepiness-restless sleep, sensory-perception symptom cluster (numbness-forgetfulness-shortness of breath-sadness-dry mouth), and digestive system symptom cluster (nausea-vomiting-loss of appetite). Fatigue was the sentinel symptom of the neuro-sleep symptom cluster, numbness was the sentinel symptom of the sensory-perception symptom cluster, and nausea was the sentinel symptom of the digestive system symptom cluster. Conclusion Early postoperative breast cancer patients experience multiple symptom clusters, with sentinel symptoms existing in each cluster. Healthcare staff should develop intervention measures based on sentinel symptoms to improve the efficiency of symptom management and reduce the degree of symptom distress for patients.