The invention discloses a clothes treatment device and a clothes washing method thereof. The clothes treatment device comprises a clothes container, a stirring part and a magnetic force driving part.The stirring part is rotatably arranged inside the clothes container and provided with a first magnetic pole, and the magnetic force driving part is arranged on the clothes container and provided witha second magnetic pole which is attracted to the first magnetic pole and arranged to move after power is supplied to drive the stirring part to stir through the attracting first magnetic pole. According to the embodiment of the clothes treatment device, magnetic field force is adopted as power for driving the stirring part to rotate, washing noise and vibration are lowered, and the using comfortof a user is improved.