Method for installing a rotor blade on a wind turbine, wherein the rotor blade has a blade root for fastening the rotor blade to a hub and a blade tip facing away from the blade root and a longitudinal axis, wherein the longitudinal axis runs from the blade root to the blade tip and the method comprises the steps of: - hoisting the component using a crane, - recording measurement data relating to the position, height position, inclination of the longitudinal axis, orientation of the longitudinal axis in a horizontal plane and rotational position of the rotor blade about the longitudinal axis of the rotor blade using at least one measuring means (20, 22, 26, 38, 30) during the hoisting, wherein at least some of the measurement data is recorded via tensile sensors, wherein one tensile sensor is arranged in a guide rope, which is connected to a blade tip of the rotor blade and another tensile sensor is arranged in another guide rope which is connected to a blade root of the rotor blade, wherein the guide ropes (14,16) are guided downwardly to the ground, - transmitting the measurement data to at least one monitoring station for monitoring the hoisting and to at least one control facility for controlling the position and/or orientation of the component, wherein the inclination and/or orientation in the horizontal plane is set via at least one of the guide ropes (14, 16) on the basis of the transmitted and/or evaluated measurement data and - forces prevailing in the guide ropes are illustrated in graphic form as well as the position and angular orientation of the longitudinal axis of the rotor blade in a horizontal plane, an inclination of the longitudinal axis from the horizontal plane and a rotation about the longitudinal axis at the monitoring station. - hoisting the component using a crane, - recording measurement data relating to the position, height position, inclination of the longitudinal axis, orientation of the longitudinal axis in a horizontal plane and rotational position of the rotor blade about the longitudinal axis of the rotor blade using at least one measuring means (20, 22, 26, 38, 30) during the hoisting, wherein at least some of the measurement data is recorded via tensile sensors, wherein one tensile sensor is arranged in a guide rope, which is connected to a blade tip of the rotor blade and another tensile sensor is arranged in another guide rope which is connected to a blade root of the rotor blade, wherein the guide ropes (14,16) are guided downwardly to the ground, - transmitting the measurement data to at least one monitoring station for monitoring the hoisting and to at least one control facility for controlling the position and/or orientation of the component, wherein the inclination and/or orientation in the horizontal plane is set via at least one of the guide ropes (14, 16) on the basis of the transmitted and/or evaluated measurement data and - forces prevailing in the guide ropes are illustrated in graphic form as well as the position and angular orientation of the longitudinal axis of the rotor blade in a horizontal plane, an inclination of the longitudinal axis from the horizontal plane and a rotation about the longitudinal axis at the monitoring station.