Hearth pressure control method and hearth pressure control system

The invention discloses a hearth pressure control method and a hearth pressure control system. The hearth pressure control method includes that setting a loop regulating module for hearth pressure regulation and setting a unusual service condition identifying loop before setting the loop regulating module, wherein the control mode for the unusual service condition identifying loop includes that doing not regulate when the hearth pressure is lowered quickly, and quickly regulating when the hearth pressure is restored and increased in a positive mode. Through arranging the unusual service condition identifying loop in a hearth pressure control loop, a negative pressure regulating loop is capable of acting quickly and correctly under such unusual service conditions as slag dropping, the regulating speed and precision are improved, and accordingly the loop adaptability is improved.