The invention discloses a magnetizing cutter, a machining method and using method thereof, a cutting fluid and a preparation method, and relates to the technical fields of cutting tools and magnetic fluid preparation. Firstly, the cutter is magnetized, and then the surface texture morphology is machined on the cutter, wherein the surface texture morphology is micro-groove texture morphology or a flow guide groove; the surface texture morphology is filled with the magnetic fluid cutting fluid, wherein the magnetic fluid cutting fluid can be continuously added in the cutting process. The surfacetexture morphology can achieve the effects of flow guide, magnetic fluid storage, friction reduction and abrasion reduction. The defects that a solid lubricant cannot be supplemented after being consumed, and a cutting fluid in a traditional cutting fluid application method cannot reach the position, with the highest temperature, of a cutting edge are overcome. The durability and cutting efficiency of the cutter are improved, and the workpiece surface machining quality is ensured.