SR-Mag™ is a fishing tool for recovering iron scraps and dirt which are generated during the cleaning operation of petroleum, geological drill and casing repair and cannot be returned by circulating liquid; wherein, magnetic scraps in the dirt will be attached on external pipe in the position of magnetic ring, and those cannot be attached for circulation will deposit inside the recovery barrel and then be brought out of the well. It possesses advantages such as simple structure, convenient operation and reliable performance. It can utilize the permanent magnet of itself to attract small objects which fall off, thus effectively fishing this kind of fallen objects, and realizing the purpose of purifying the bottom hole.