The invention relates to an oil-leak proof bearing system, and the system includes a bearing, an oil-leak proof cover and a rotor shaft. The center portion of the oil-leak proof cover defines a through hole, and the inner wall defining the through hole is provided with at least one first guiding groove thereon extended obliquely downward from the upper edge of the inner side face to force oil dispersed by the rotor shaft to flow back into the bearing system. The bottom surface of the oil-leak proof cover, contacting the bearing, is provided with second guiding grooves extending radially approximately from the center thereof. The capillarity of the second guiding grooves guides the oil dispersed by the rotor shaft to flow radially. The design of the first and second guiding grooves prevents the bearing system from leakage of lubricating oil, and provides a closed oil loop for operation.