The invention discloses a fatliquor for natural leather. The fatliquor comprises, by weight, 20-30 parts of poly-hydroxyethyl castor oil, 2-4 parts of methanol, 20-60 parts of olive oil, 2-4 parts of copper stearate, 6-8 parts of dimethylol urea resin, 10-20 parts of polyurethane, 10-30 parts of stearic acid, 8-16 parts of octanol, 4-8 parts of oleic acid, 2-4 parts of sulfuric acid, 6-12 parts of sodium hydroxide, 10-18 parts of naphthenic acid, 2-8 parts of glacial acetic acid and 8-16 parts of acrylamide. According to the fatliquor for the natural leather, preparation is easy; adopted production raw materials are non-toxic; and fabric treated with this finishing agent can prevent shrinkage and wrinkling, the shaping effect is good, ironing is free, and the fabric has the characteristics of being level, smooth, full, non-fouling and the like.