The invention is water-soluble self-emulsifying coupled modified silicone oil composite and an application in pickling, tanning and dyeing of leather, which is characterized in that the water-soluble self-emulsifying coupled silicone oil composite after modification is adopted to carry out oil pretanning, tanning, softening, dyeing and setting treatment on pickled skins of animals in a revolving drum. The crust leather to be coated has the advantages of plumpness, softness, no loose grain, good elasticity, good foaming sense and velvet silicon sense after treatment. By adopting the composite and the application method thereof to carry out oil pretanning, tanning, softening, dyeing and setting treatment, the quality of finished leather can be improved and stabilized, the production cost isreduced, the workshop sections such as wet blue pickling and degreasing, chrome retanning, alkali extraction overnight, neutralization and the like in the traditional leather making technique can be completely canceled, and the usage amounts of dye, fatliquor, stuffing and the like can be reduced, water washing is avoided by twice, thus saving more than 40% of water, shortening more than one third of the production period, reducing more than half of subsequent milling time, greatly stabilizing and simplifying the technique procedures, being easy to control the leather quality, and obviously reducing pollutant discharge in the traditional leather-making workshop sections of tanning, pretanning and dyeing water yard and lowering energy consumption such as water, electricity, manpower and the like.