A coal and gangue identification device is disclosed. The device includes a rotary supporting frame, a water injection unit, a weighing unit, a liquid level detection device and a processing module. The rotary supporting frame is provided with a loading unit used to load a mineral aggregate. The rotary supporting frame is used to drive the loading unit to rotate on a horizontal plane. In the rotating process of the rotary supporting frame, the loading unit cyclically passes through a water injection region, a material adding region, a volume measurement region and an unloading region which are sequentially disposed on a rotation trajectory of the rotary supporting frame. The water injection unit is used to inject water to the loading unit of the water injection region.