The utility model discloses an unmanned helicopter tailspin wing pitch -changing mechanism, including coda wave case main part, adjust the slider and tailspin wing holder, drive rocker arm support goes up the articulated drive rocking arm that has, the one end that the drive rocking arm was kept away from to the adjust the slider push -and -pull rod is equipped with adjust the slider, and two adjust the slider push -and -pull rods and adjust the slider hinged joint, adjust the slider's both sides articulate has tail pitch pull rod, the one end that adjust the slider was kept away from to tail pitch pull rod is equipped with tailspin wing holder, be equipped with the tailspin pivot among the adjust the slider, the tailspin pivot runs through the setting in coda wave case main part, adjust the slider and tailspin wing holder, and the the central axis of the the central axis of coda wave case main part, adjust the slider and tailspin wing holder and tailspin pivot is located same straight line, be provided with steering wheel hub connection head on the drive rocking arm. The utility model discloses increased the life of adjust the slider and tailspin pivot, make the motion of tail rotor system during operation more smoothly, more stable.