The invention relates to a gas stove dry-burning-prevention method. When a
diffuse reflection photoelectric switch detects that a person exists in front of a cooking bench, a dry-burning-prevention device is not started; when the
diffuse reflection photoelectric switch detects that no person exists in he cooking bench, and an
infrared sensor detects that the person exists in front of the cooking bench, according to the fire magnitude,
delay sound alarm is carried out, and if unmanned operation is carried out, the dry-burning-prevention device is started; when the
diffuse reflection photoelectric switch detects that no person exists in the cooking bench, and the
infrared sensor detects that the person does not exists in front of the cooking bench, the dry-burning-prevention device is started; after the dry-burning-prevention is started, according to a sheltered photosensitive
diode, the position of a rotary knob is judged, the current fire magnitude is determined, if the current fire islarge, after it continues for T1, an alarm is given out, a motor is controlled to rotate, and the rotary knob is rotated
clockwise until the rotary knob is closed; if the current fire is the medium heat, after it continues for T2, the alarm is given out, and the motor is controlled to be rotated; and if the current fire is the small fire, after it continues for T3, the alarm is given out, and themotor is controlled to rotate.