With rapid sponsorship and widely spreading of sustainable development theory, the research on the sustainable development indicator systems and its evaluation became increasingly an important issue for small watershed. Small watershed was thought to be the most basic operation unit for watershed sustainable development realization, building its sustainable development indicator system was regarded as the basic approach of realizing its sustainable development. Taking Puwa small watershed as study object, this paper quantitative analysis that the status of small watershed sustainable development by using AHP-PCA method. In this paper, taking AHP-PCA method as a powerful tool, by calculating comprehensive evaluation values of sustainable development as well as objective analysis of the level of sustainable development in different years the sustainable development situation of Puwa small watershed was evaluated. Corresponding strategies were put forward to supply relational decision-making departments with reference.