A portable supporting frame for a cutting machine includes a leg frame, a tabletop frame, and a frame locker. The leg frame includes two opposing pairs of first and second supporting legs. The tabletop frame includes two table arms pivotally connected to the first crossed legs respectively. The frame locker is used for locking the top ends of the second crossed legs to the table arms respectively to retain the portable supporting frame at a set up position. When the frame locker is released, the tabletop frame is adapted to pivotally fold at 180° to overlap on the folded leg frame at a folded position.