A robot control system includes an operation command output unit which outputs an operation command of a motor, a position detection unit which is provided on the motor to detect the position of a control shaft, a stop signal output unit which outputs a stop signal to stop the robot when the speed of the control shaft acquired from the position detection unit exceeds a speed threshold value, and an operation command interruption unit which interrupts the operation command outputted from the operation command output unit when the stop signal is outputted.