This study aimed to investigate the prevalence, severity, and associated factors of menopausal symptoms among middle-aged Chinese women. A multicenter, population-based cross-sectional study was conducted, involving 7,485 women aged 40-69 years from Zhejiang Province, China. Data on demographic characteristics, socioeconomic status, and lifestyle factors were collected using a structured questionnaire. Menopausal symptoms were assessed using the modified Kupperman Menopausal Index (mKMI), and multinomial logistic regression models were employed to identify factors linked to menopausal syndrome. The participants had a mean age of 52.4 (±7.3) years, with 46.1% being nonmenopausal and 53.9% postmenopausal. The most common menopausal symptoms were sexual problems (43.6%), insomnia (33.1%), and fatigue (27.5%). Among nonmenopausal women, insomnia was the most prevalent symptom (26.9%), whereas postmenopausal women most frequently reported sexual problems (61.1%). Both the prevalence and severity of menopausal symptoms significantly increased from nonmenopausal to postmenopausal status (p < 0.001). Significant associations were found between menopausal syndrome and factors such as age, menopausal status, education level, residence, income, passive smoking, physical activity, and occupational toxic exposure (p < 0.05). In conclusion, Sexual problems are the most bothersome menopausal symptom among females in southeast China. Postmenopausal females experience more prevalent and more severe symptoms. Additionally, socioeconomic and lifestyle factors play a significant role in menopausal syndrome.