The invention relates to a composite rotor blade for an unmanned helicopter and a manufacturing method thereof. The composite rotor blade comprises an upper airfoil
skin, a lower airfoil
skin, an upper airfoil part of a C-shaped crossbeam, a lower airfoil part of the C-shaped crossbeam, a
leading edge balance weight lead strip, a
paddle root lining, a foam core, a
paddle tip balance weight lead block and a balance weight
pipe, wherein the upper airfoil
skin and the lower airfoil skin are closed to form the profile of a blade; the
leading edge balance weight lead strip is arranged on the
leading edge of a blade airfoil profile; the upper airfoil part of the C-shaped crossbeam and the lower airfoil part of the C-shaped crossbeam are combined to form the C-shaped crossbeam; the C-shaped crossbeam is close to the leading edge balance weight lead strip; the foam core is filled into a
trailing edge part of the C-shaped crossbeam; and in order to regulate balance, the
paddle tip balance weight lead block and the paddle tip
trailing edge balance weight
pipe are cured on the front section of the blade, and the paddle root lining is arranged on the rear section of the blade.