The invention discloses a leather fogging treating agent which is prepared from the following raw materials in parts by weight: 50-60 parts of water-based polyurethane resin, 20-35 parts of deionized water, 1-5 parts of emulsified silicone oil, 0.5-2 parts of organic silicon leveling agent, 1-7 parts of nonionic water-based polyurethane thickener, 1-5 parts of superfine nano scrap rubber micropowder, 1-4 parts of kaolin and 0.5-3 parts of silane coupling agent. The superfine nano scrap rubber micropowder, which is coated by the coupling agent and added into the treating agent, can enhance the binding force between the resin and rubber micropowder, so that the bonding strength between the treating agent and leather surface is enhanced, and the coating can not easily shed. The leather surface can display the stereoscopic fogging effect, and thus, the leather fogging treating agent has better surface decoration property. The preparation process adopts an ultrasonic treatment mode, so that the obtained emulsion is more uniform, and the molecules are bonded more firmly, thereby improving the quality of the treating agent and prolonging the shelf life and use effect.