A cup device for heating, stirring and foaming liquid food comprising: a cup, a cup cover, a handle, a stirrer, a motor drive disk, a first magnet, an electric motor, a hot plate, a dry thermostat, a thermostat, a micro switch, a transformer, a controller, a heating base, buttons, a button circuit board, connecting wires and bolts; wherein: a first retaining ring is set into a center hole of the hot plate; a heat insulation ring is set into an inner ring; the thermostat is inserted into a thermostat ring and a spring is set outside of the thermostat ring; the thermostat ring is put into a hole of the thermostat of the hot plate; the electric motor is set on a retaining ring with the bolts; the motor drive disk with the first magnet is inserted into a shaft of the electric motor; a handspike is pushed into a hole of the retaining ring; the micro switch is set on the retaining ring such that a button of the micro switch is against the handspike; the retaining ring is pushed into the inner ring to fix the hot plate; the inner ring is inserted into a shell of the heating base; the buttons, a plastic pad and the button circuit board are set in a button hole of the shell of the heating base; the dry thermostat is set on the hot plate; the transformer and the controller are fixed on a bottom cover after inner wires are connected; the bottom cover with the transformer, the controller and wires are fixed tightly on the retaining ring and the shell of the heating base; a stirring shaft is riveted to a bottom of the cup; the stirrer with a second magnet inside is set into the stirring shaft; the handle is tightly fixed outside the cup; the cup cover is put on the cup; and the cup is put into the hole on the shell of the heating base and on the hot plate. a cup, a cup cover, a handle, a stirrer, a motor drive disk, a first magnet, an electric motor, a hot plate, a dry thermostat, a thermostat, a micro switch, a transformer, a controller, a heating base, buttons, a button circuit board, connecting wires and bolts; wherein: a first retaining ring is set into a center hole of the hot plate; a heat insulation ring is set into an inner ring; the thermostat is inserted into a thermostat ring and a spring is set outside of the thermostat ring; the thermostat ring is put into a hole of the thermostat of the hot plate; the electric motor is set on a retaining ring with the bolts; the motor drive disk with the first magnet is inserted into a shaft of the electric motor; a handspike is pushed into a hole of the retaining ring; the micro switch is set on the retaining ring such that a button of the micro switch is against the handspike; the retaining ring is pushed into the inner ring to fix the hot plate; the inner ring is inserted into a shell of the heating base; the buttons, a plastic pad and the button circuit board are set in a button hole of the shell of the heating base; the dry thermostat is set on the hot plate; the transformer and the controller are fixed on a bottom cover after inner wires are connected; the bottom cover with the transformer, the controller and wires are fixed tightly on the retaining ring and the shell of the heating base; a stirring shaft is riveted to a bottom of the cup; the stirrer with a second magnet inside is set into the stirring shaft; the handle is tightly fixed outside the cup; the cup cover is put on the cup; and the cup is put into the hole on the shell of the heating base and on the hot plate. a first retaining ring is set into a center hole of the hot plate; a heat insulation ring is set into an inner ring; the thermostat is inserted into a thermostat ring and a spring is set outside of the thermostat ring; the thermostat ring is put into a hole of the thermostat of the hot plate; the electric motor is set on a retaining ring with the bolts; the motor drive disk with the first magnet is inserted into a shaft of the electric motor; a handspike is pushed into a hole of the retaining ring; the micro switch is set on the retaining ring such that a button of the micro switch is against the handspike; the retaining ring is pushed into the inner ring to fix the hot plate; the inner ring is inserted into a shell of the heating base; the buttons, a plastic pad and the button circuit board are set in a button hole of the shell of the heating base; the dry thermostat is set on the hot plate; the transformer and the controller are fixed on a bottom cover after inner wires are connected; the bottom cover with the transformer, the controller and wires are fixed tightly on the retaining ring and the shell of the heating base; a stirring shaft is riveted to a bottom of the cup; the stirrer with a second magnet inside is set into the stirring shaft; the handle is tightly fixed outside the cup; the cup cover is put on the cup; and the cup is put into the hole on the shell of the heating base and on the hot plate.