The invention relates to a garment local stain cleaning device and a beating mechanism thereof. The garment local stain cleaning device comprises a ribbed plate suitable for fixing the beating mechanism into the garment local stain cleaning device, a sliding hole fixedly arranged in the ribbed plate, a sliding shaft penetratingly arranged in the sliding hole and suitable for sliding and rotating in the same, a brush head fixedly arranged at one axial end of the sliding shaft and a round plate fixedly arranged to a round structure at the other axial end of the sliding shaft, the brush head is suitable for being arranged towards garment cloth, and the brush head, the round plate and the sliding shaft are coaxially arranged.