Objective To investigate the wild mushroom species causing a food poisoning in Changxing County, Zhejiang Province, analyze the causes of the incident and summarize the experience of investigation,purposed to provide references for prevention and proper treatment. Methods The epidemiological investigation, morphological identification and phylogenetic identification were used to analyze the poisoning event. Results Epidemiological investigation found that three patients were poisoned due to mushrooms picked by themselves, among which 1 case was severe and 2 cases were mild, and the attack rate was 100%. The main clinical manifestations were nausea, vomiting and diarrhea. One patient developed severe rhabdomyolysis poisoning after a short pseudo-recovery period. The highest level of serum creatine kinase (CK) was 318 200 U/L. The mushroom samples were identified as Russula subnigricans by morphological identification and phylogenetic identification. Conclusion This incident was a case of mushroom poisoning caused by accidental ingestion of Russula subnigricans. The key to prevent poisonous mushroom poisoning is to carry out publicity and education, enhance people's awareness of prevention and improve the ability of medical institutions to diagnose and treat poisonous mushrooms.