A torque assisting device, characterized in that the device comprises: a rotating mechanism on which a load is provided; a fixing cylinder of which a circumference of one end surface is provided with a continuous motion trajectory having an inclination angle; and an axially elastic force-applying mechanism connected with the fixing cylinder , wherein one end of the rotating mechanism is abutted on the continuous motion trajectory and the rotating mechanism rotates about an axis of rotation (A-A) along the continuous motion trajectory ; and the inclination angle of the continuous motion trajectory is set according to a torque generated by the gravity of the load based on the following equation: β = arctan m × g × L × sin ⁢ α F × r wherein m is a mass of the load, g is the gravitational acceleration, L is a vertical distance from the centre of gravity of the load to the axis of rotation (A-A), α is a rotation angle of the centre of gravity of the load, r is a vertical distance from the continuous motion trajectory to the axis of rotation (A-A), and F is an axial thrust force applied to the abutting point between the rotating mechanism and the continuous motion trajectory by the force-applying mechanism , and a vertical distance from an action point of the thrust force to the axis of rotation (A-A) is equal to a vertical distance from the continuous motion trajectory to the axis of rotation (A-A). a rotating mechanism on which a load is provided; a fixing cylinder of which a circumference of one end surface is provided with a continuous motion trajectory having an inclination angle; and an axially elastic force-applying mechanism connected with the fixing cylinder , wherein one end of the rotating mechanism is abutted on the continuous motion trajectory and the rotating mechanism rotates about an axis of rotation (A-A) along the continuous motion trajectory ; and the inclination angle of the continuous motion trajectory is set according to a torque generated by the gravity of the load based on the following equation: β = arctan m × g × L × sin ⁢ α F × r wherein m is a mass of the load, g is the gravitational acceleration, L is a vertical distance from the centre of gravity of the load to the axis of rotation (A-A), α is a rotation angle of the centre of gravity of the load, r is a vertical distance from the continuous motion trajectory to the axis of rotation (A-A), and F is an axial thrust force applied to the abutting point between the rotating mechanism and the continuous motion trajectory by the force-applying mechanism , and a vertical distance from an action point of the thrust force to the axis of rotation (A-A) is equal to a vertical distance from the continuous motion trajectory to the axis of rotation (A-A). wherein m is a mass of the load, g is the gravitational acceleration, L is a vertical distance from the centre of gravity of the load to the axis of rotation (A-A), α is a rotation angle of the centre of gravity of the load, r is a vertical distance from the continuous motion trajectory to the axis of rotation (A-A), and F is an axial thrust force applied to the abutting point between the rotating mechanism and the continuous motion trajectory by the force-applying mechanism , and a vertical distance from an action point of the thrust force to the axis of rotation (A-A) is equal to a vertical distance from the continuous motion trajectory to the axis of rotation (A-A). <EOS>