The utility model provides an automatic speed limit structure of vertical axis aerogenerator blade, includes girt and the blade of assembly on the girt with the perpendicular rotation axis connection of aerogenerator, the outside end of girt is equipped with the U -shaped connecting seat, and the medial surface of blade is equipped with is connected the otic placode with U -shaped connecting seat complex, and blade and U -shaped connecting seat connect through erecting the connecting axle hinge of putting, at the preceding side's of the setting pipe of fixing of girt, the square intraductal spring that is equipped with, the fixed square pipe end of taking central screw hole that sets up of medial extremity of side's pipe blocks up, is equipped with adjusting screw with this center screw hole cooperation, and dress square cross -section's ejector pin is held in the outside of side's pipe, and semi -cylindrical surface is set to the outside end of ejector pin, and the anterior of connection otic placode is given prominence to in the preceding terminal surface of U -shaped connecting seat to at the inboard setting of its protruding portion and the semi -cylindrical surface complex arc groove of ejector pin. The utility model discloses simple structure, preparation and maintenance cost are low, the adaptability ability is good, the reliability is high, can realize vertical axis aerogenerator's real -time automatic speed limit.