Propeller hub structure of variable pitch propeller

The variable-pitch propeller hub structure comprises an upper propeller hub, a lower propeller hub, a propeller hub connecting bolt set, a propeller clamp and propeller blade variable-pitch assembly, a rotating shaft and an anti-loosening bolt set, rotating grooves are formed in the upper propeller hub and the lower propeller hub, and the propeller clamp and propeller blade variable-pitch assembly comprises a variable-pitch shaft, a thrust bearing, a deep groove ball bearing, a propeller clamp, a propeller blade and a propeller blade connecting bolt set. A shaft head of the variable-pitch shaft is installed on the rotating groove, a shaft body of the variable-pitch shaft is connected with inner rings of the thrust bearing and the deep groove ball bearing, outer rings of the thrust bearing and the deep groove ball bearing are installed on the inner wall of the upper propeller hub and the inner wall of the lower propeller hub, the propeller blades are installed on the propeller clamp, and the propeller clamp is