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).