In order to solve the problem that the traditional measures are not systematic and easy to be influenced by subjective factors in the construction of outdoor activity rest spaces for the elderly in the urban communities, which cannot obtain the real needs of the elderly and cannot quickly assess and predict the distribution of rest spaces. The suitable outdoor walking distance (SOWD) is defined here as the distance accepted by most of young-elderly and old-elderly to walk outside the home in daily life without break. To understand the relationship between SOWD and the rest space networks, we proposed an approach in which each variable of SOWD can be analyzed different weight with analytic hierarchy process. In this way, 9 old residential quarters in Nanjing were used to investigate to discover the law of the elderly outdoor activities, so as to establish a conceptual model of outdoor activity rest space networks model for the elderly in old communities. The results show that the SOWD can objectively evaluate the level of elderly outdoor activity in urban old residential quarters. The distribution model based on SOWD can quickly identify potential imperfections in construction. Therefore, the SOWD is a key factor in the construction of outdoor activity rest spaces for the elderly.