The invention discloses a method for evaluating the adequacy of a power grid line considering the uncertainty of wind power output, which comprises the following steps: calculating the output of a wind turbine generator system and the uncertainty value of the output of the wind turbine generator system; establishing a grid line adequacy index Z s, wherein the Zs is equal to the ratio of the sum ofthe actual transmission capacity value of a grid transmission line on the maximum load day of a year and the wind power output uncertainty power value to the thermal limit transmission capacity valueof the transmission line; Calculating Zs and evaluating the line adequacy with reference range of line adequacy index; The closer Z s is to the lower limit of the reference range of the grid line adequacy index, the more suitable and economical the region is to be evaluated for new energy consumption and planning. The invention fills in the blank of the method for evaluating the adequacy of the grid line considering the uncertainty of the wind power output, evaluates the adequacy of the grid line under the background of new energy consumption from a macroscopic point of view, and provides a basis for the grid planning and design. The invention is applicable to the field of power network planning.