A balancer abnormality detection system includes: a robot; a motor configured to operate the robot; a balancer provided in the robot and configured to generate assist torque which assists power of the motor with force generated by elastic bodies; and a controller configured to detect abnormality of the balancer by measuring a current value of the motor operated to keep a posture of the robot during standby of the robot and comparing the current value with a current command value of the motor necessary for keeping the posture of the robot.