The invention discloses a balance degree detection and protection system based on the superconducting magnet, including a superconducting magnet power system, a quench detection module, a quench protection module and a superconducting magnet; the quench detection module is connected with the superconducting magnet for detecting the middle voltage and the voltage across the superconducting magnet,the middle voltage and the voltage across the superconducting magnet are used to calculate the balance degree value of the superconducting magnet, and the detected balance value is sent to the superconducting magnet power system; the superconducting magnet power system is used for receiving the balance degree value sent by the quench detection module, and the quench protection module is controlledaccording to the detected balance degree value; the quench protection module is connected with the superconducting magnet to protect the superconducting magnet. In the system, that whether the quenching phenomenon exists in the superconducting magnet is detected by the quench detection module. When the quench phenomenon occurs, the superconducting magnet power system controls the quench protection module so that the energy in the superconducting magnet can be released and protection of the superconducting magnet and the power system is effectively achieved.