As the main economic activity subjects in the key ecological function area, the farmers' perception of ecosystem services directly affects their environmental behavior, and is related to the performance of the main functions and the implementation effectiveness of the protection plans. Taking the Gannan Plateau, located in the eastern edge of the Tibetan Plateau, as a case study area and based on the household survey data, this paper analyzed the farmers' perception of the ecosystem services of grassland, forest, wetland, and farmland. We also analyzed the factors affecting the farmers' perception of ecosystem services by the orderly multiple linear regression model. The results showed that: (1) the diversified perception of farmers on forest, grassland, farmland, and wetland ecosystem services in Gannan Plateau was weakened in turn, among which the diversified perception of farmers in planting-pasturing area was stronger than that in the planting and pastoral areas. (2) The farmers' perception of the importance, manageability, vulnerability, and damage of forest, grassland, farmland, and wetland ecosystem services decreased successively, and the attribute perception of farmers in different regions was different. (3) The individual and family characteristics were important factors affecting the farmers' diversified perception of ecosystem services. The individual and family characteristics, environmental policies are important factors affecting the farmers' perception of ecosystem service attributes.