The invention relates to a method and a device for automatically regulating a swaying angle of a household appliance. The interior of a household appliance head is provided with an actuating mechanism, an infrared human body detection system and an electric control system, wherein the actuating mechanism consists of a speed reducing motor and a transmission mechanism, the infrared human body detection system consists of an infrared receiving head and a condenser lens, and the electric control system consists of a signal processing circuit and a control circuit; the household appliance head reciprocally sways within the minimum angle range including all users and timely adjusts the size and the area of the swaying angle according to the number of the users and the position change; and the transmission mechanism is a crank-link mechanism or a gear mechanism and is used for changing the back-and-forth rotation of the speed reducing motor into the reciprocal swaying of the household appliance head. The invention can ensure that wind or hot air from the household appliance is gathered on the user body maximally, enable the user to feel comfortable and convenient and prevent the energy waste caused by blowing the wind or hot air into an unmanned area.