The invention discloses a structure for preventing inner flange joint faces of wind power towers from cracking. The structure comprises inner flanges of two towers connecting the barrel walls of the two towers, the inner flanges of the two towers are locked through a plurality of flange bolts, at the position close to the mutually attached surfaces of the inner flanges of the two towers, a slope opening is formed in the inner side of the inner flange of each of the two towers, and the slope openings in the inner flanges of the two towers are close to each other to form a wedges-shaped groove; an arc-shaped wedge is inserted into the wedge-shaped groove, and the upper side and the lower side of the arc-shaped wedge are attached to the two sides of the wedge-shaped groove; the two ends of a locking long-arc plate are connected with the inner flanges of the two towers through lock bolts respectively, and the locking long-arc plate is pressed against the outer end of the arc-shaped wedge in an abutting mode. The structure for preventing the inner flange joint faces of the wind power towers from cracking is provided, and the structure can effectively prevent the inner flange joint faces of the wind power towers from cracking, and has the effect of safety protection.