The invention relates to a power generation windmill group, belonging to the technical field of generating sets. The power generation windmill group comprises a main shaft, vanes, vane sleeve shafts, a supervoltage sensor, a connector for a phase converter at the root parts of the vanes, a power transmission gear, a fan cover, vane groups with diverse directions. The power generation windmill group is characterized in that the diameters of the vanes of the windmill can be designed to be from large to small, or be equal to one another, or be small to large; a plurality of vane groups are connected in series on the same shaft, and the forced directions of the vanes are mutually reversed. When wind passes through the first vane group, and the second vane group is blown to rotate by the rest energy to do work, and so on. When the wind force exceeds a preset insurance value, the supervoltage sensor automatically causes the vanes to rotate, surfaces contacting the wind become smaller and smaller until being smallest, and the direction is not changed, thereby playing the function of protecting equipment and increasing the power generation efficiency.