Taking the subalpine grassland wind farm located on Gaoben Mountain in Xundian County, Yunnan Province as an example, a land damage evaluation model was constructed to effectively determine the extent of land damage caused by construction in the area. Seventeen evaluation indicators (10 soil-related and 7 damage-related) were selected. Indicator weights were determined using the Delphi-Fuzzy-AHP (hereafter referred to as DFA) method. A possibility function was established by integrating the grey clustering method. Observed values were used to calculate possibility function values for seven evaluation units (two in Phase I wind turbine zones, two in Phase II wind turbine zones, tailings pond, quarry, and original topography) using observed values. Finally, by comparing the magnitude of the coefficients, the land damage severity grades for each evaluation unit were determined. The results are as follows :(1) The weight of damage element (0.642) is significantly higher than that of soil element (0.358); the core factor of damage element is the slope length of damaged surface (0.183) and vegetation cover (0.168), reflecting its direct impact on engineering safety and soil erosion; the weight of soil capacity (0.0695) and organic matter content (0.0504) in the soil element is the highest, which is mainly due to the construction of the wind turbine. (2) Grey clustering evaluation shows that the soil structure changes and fertility decline. (2) Grey clustering evaluation shows that the damage degree of the first phase of the project is moderate (grade III), the second phase of the wind turbine area is very strong (grade V), the slag dump is strong (grade IV), the quarry is severe (grade Ⅵ), and the original landscape is light (grade II). (3) The difference in the degree of damage originates from the intensity of construction disturbance and the restoration cycle: the first phase of the project due to the preservation of surface soil and natural recovery for a long time, the ecological restoration effect is better; the second phase of the project is a large area of disturbance and the completion of a short period of time, the recovery of vegetation is lagging behind. At present, the land damage of Gaoben Mountain wind farm is relatively serious, and its land damage is dominated by construction disturbance, and the high weight of the damage elements highlights its priority for engineering safety and ecological risk. The study verified the applicability of the DFA-Gray clustering model, which can provide a scientific basis for ecological restoration and management of other wind farms.