A motor information acquisition system is provided that acquires information representing an operation state of a motor included in a machine tool in order to monitor a state of the machine tool and that includes a motor control device configured to control the motor based on control data, a timing generation section configured to generate acquisition timing of the information representing the operation state of the motor based on the control data, a rotor magnetic flux reduction command output section configured to output a command for reducing a magnetic flux density of a rotor of the motor to the motor control device when the acquisition timing is reached, and a motor information acquisition section configured to acquire information representing the operation state of the motor when the magnetic flux density of the rotor is reduced by the command.