Fastening method for flange bolt of wind power tower

The invention relates to the technical field of wind power generation, and discloses a wind power tower flange bolt fastening method which comprises the steps that S1, a walking mechanism walks to a bolt needing to be fastened; s2, the lifting base drives the fastening assembly to move downwards, and the current descending distance of the fastening assembly is obtained; when the current descending distance is a first preset descending distance, entering a step S3; when the current descending distance is located at a second preset descending distance, entering a step S4; s3, the lifting seat drives the fastening assembly to move downwards until the flexible chain is loosened; the fastening sleeve rotates relative to the fastening assembly until the nut is sleeved with the fastening sleeve; and S4, the lifting base drives the fastening assembly to move downwards till the descending distance of the fastening assembly is not changed, and when the flexible chain is loosened, the fastening sleeve tightens the bolt.