The study aimed to examine the current situation and influencing factors of social support and social isolation among older adults in the community，to provide a reference for community-based mental health interventions for this population. This study conducted an on - site survey using convenience sampling among older adults in 2 communities in Hefei，Anhui Province，from June to July 2024. The results showed that the prevalence of social isolation among older adults was 36.8%. Among the targeted samples，59.5% could obtain information support，58.2% could obtain emotional support，47.4% had access to appraisal support from family or friends，and 65.8% could obtain specific instrumental support from family and friends when needed. Logistic regression analysis revealed that social participation and specific instrumental support were influencing factors contributing to the social isolation of older adults in the community. Efforts should be made to strengthen social support and social network interventions based on community-based support and family-based support for older adults to improve their mental health status.