Abstract: An oil expeller has a stand with an upper cylinder and a lower cylinder, an oil filter mounted on the stand and a control device controlling the upper and lower cylinders. The oil filter has a filter tank and two pressing panels mounted in the filter tank. Raw materials are disposed between the pressing panels. Thus, the upper cylinder presses a corresponding pressing panel and the raw materials to extract oil from the raw materials. The lower cylinder pushes a corresponding pressing panel and waste product out of the filter tank. The oil expeller takes up little space, operates easily and extracts oil from the raw materials 40 and removes the waste product alternately. Moreover, the user is allowed to provide fresh oil based on his needs when extracting oil from a suitable amount of raw materials.