External connectivity refers to the service opportunities provided by community open spaces that are influenced by the factors such as traffic distance, road conditions, residence patterns, and population distribution. It is an important factor in determining access to community open spaces. This has important implications for promoting walking behavior and community physical activity among aging urban populations. Using the accessibility evaluation method, we proposed an external connectivity of the community open spaces model from the community perspective and conducted an empirical study using the Overseas Chinese Town community in Shenzhen as an example. External connectivity of the community open spaces can be used to evaluate the efficiency of community open spaces, serving as a reference for open space optimization. Moreover, it has applicable value in promoting physical activity and healthy aging among older adults.