Oil-water separation device and oil tank

The utility model discloses an oil-water separation device and an oil tank, and relates to the technical field of automobile parts. The oil-water separation device is connected to an oil discharge base at the bottom of the oil tank body and comprises a water storage device and a fixing piece, the water storage device is of a hollow annular structure, an annular opening is formed in the inner annular wall of the water storage device, and the fixing piece penetrates through the hollow part of the water storage device to connect the water storage device with the oil discharge base; a first through hole is formed in the fixing piece so that the oil tank body can communicate with an inner cavity of the water storage device. According to the oil-water separation device, automatic water removal of the oil tank can be achieved, the oil-water separation device has a large volume on the premise that a small vertical space is occupied, and the technical problems that the volume of a water storagedevice is too small and