Objective This study was conducted to systematically analyze the epidemic status, core co-morbidities patterns and influencing factors of chronic diseases among elderly people aged 65 and above in FQ town in East China, so as to reveal the health burden characteristics and co-morbidities trends of the elderly population in this area, and provide empirical evidence for formulating precise prevention and control strategies and management programs for chronic diseases in accordance with the characteristics of grass-roots villages and towns. Methods A cross-sectional study design was adopted to collect health examination data of 12,028 elderly people aged 65 and above in FQ town in 2024. Prevalence and comorbidity of 8 common chronic diseases such as hypertension, diabetes mellitus and stroke were analyzed. Disease counting method was used to describe comorbidity combinations, and Apriori association rule algorithm was used to mine strong association patterns among diseases. Based on the health ecology model framework, single factor and multiple factor Logistic regression analysis were used to explore the influencing factors of chronic disease comorbidity from multiple aspects such as congenital traits, individual behavior, interpersonal network and living conditions. Results In FQ town, 64.9% of the elderly were included in chronic disease management, and the overall prevalence of chronic diseases was 20.2%. Hypertension had the highest prevalence Association rule analysis showed that the binary comorbidity pattern presented a highly concentrated feature,"diabetes→ hypertension"(Confidence 95.89%), Stroke→Hypertension (93.93% confidence) and "coronary heart disease→hypertension" There was age and gender heterogeneity in the co-morbid pattern: the co-morbid driving core shifted from metabolic diseases to "myocardial infarction→hypertension" and "chronic bronchitis→hypertension" in the age group of 75-79; the association of "chronic bronchitis→hypertension" appeared in the elderly women. Multivariate analysis showed that old age and overweight/obesity were independent risk factors for comorbidity, and obesity was the highest risk factor (OR=21.7). Conclusion Although the burden of chronic diseases in FQ town was lower than that reported in China, the metabolic and cardiovascular diseases co-morbidities pattern with hypertension as the core was very prominent and the correlation intensity was amazing. The study suggests that prevention and control of chronic diseases at the grass-roots level should break through the single-disease diagnosis and treatment thinking, implement synchronous blood pressure management for patients with diabetes and stroke, and formulate stratified and accurate health management and education strategies according to age and gender differences.