A robot control device according to an embodiment includes: an observer receiving the angular velocity of the motor and the current command value, and estimating an angular acceleration of the link, and angular velocities of the link and the motor from a simulation model of an angular velocity control system of the motor; a first feedback unit calculating an axis torsion angular velocity from a difference between the angular velocities of the link and the motor estimated by the observer, and giving feedback to the angular velocity control system; a second feedback unit feeding back the angular acceleration of the link estimated by the observer to the angular velocity control system; and a first feedback constant calculating unit compensating an end effector load mass and increases inertia at the second feedback unit when an end effector load in the nonlinear dynamic model has low inertia.