With the development of economy and society, people have growing demand for healthy living environments. However, there are more than 170,000 old residential communities in China, where aging buildings, old facilities and environmental degradation are common problems that need to be urgently improved. Determining subsidy funding and benefit evaluation is often the blind spot, posing difficulties in government decision-making. In this study, the Fuzzy Delphi Method (FDM) was first adopted to propose a set of standards for outdoor environment renovation of old residential communities in China based on the WELL Community Standard (WCS). On the basis of the I-S model and zero-one integer programming (ZOIP), an optimal decision-making model (ODM) was developed and applied in practical projects. The result showed that ODM can not only help government managers to determine the budget rationally, but also provide a way to promote multiple participations to achieve optimal improvement strategies. It is recommended that ODM should be further expanded on more projects to review and modify the application of ODM in different regions of China.