The invention discloses a rotor blade root configuration, and belongs to the technical field of helicopter rotor blade design. The rotor blade root configuration comprises a shell, girder winding pins, internal thread nuts, bearings, external thread nuts, a root skin and a propeller hub supporting arm. The shell is composed of a straight-line section and an arc-shaped section. The girder winding pins are arranged on the side, away from a blade root, of the arc-shaped section. A girder belt is connected with the blade root through the girder winding pins. The outer side of the straight-line section is connected with the root skin, and the outer side of the straight-line section and the blade root are solidified into a whole. The propeller hub supporting arm is installed in a cavity of the straight-line section, the bearings are installed between the propeller hub supporting arm and the shell, and the two sides of the bearings are separately limited by the internal thread nuts and the external thread nuts. The external thread nuts are in threaded connection with the shell and are not connected with the propeller hub supporting arm. The internal thread nuts are in threaded connectionwith the propeller hub supporting arm and are not connected with the shell. The end, close to a propeller hub, of the shell is connected with a variable-pitch rocker arm. The rotor blade root configuration has good reliability and manufacturability, and can solve the structural design problem caused by excessive load at the blade roots of rigid rotors such as ABC rotors.