The invention provides a preparation method of a
chromium-contained retaining-filling agent. The method comprises the steps that (1), 100 parts of chrome leather
scrap hydrolysate, 20 parts to 100 parts of retanning agents, 1 part to 5 parts of masking agents and 3 parts to 5 parts of fatting agents are metered, then, the masking agents and the
solid retanning agents are dissolved with water, the fatting agents are diluted and emulsified through water, and acidifying or alkalizing agents are compounded with water to form acidifying or
alkalizing agent solutions; (2), the chrome leather
scrap hydrolysate is heated to 45 DEG C to 50 DEG C under stirring, then, the chrome leather
scrap hydrolysate, the masking agents, and the
solid retanning agents or / and liquid-state retanning agents which are at the same temperature and obtained in the step (1) are added into the chrome leather scrap hydrolysate and are evenly mixed, then, the acidifying or
alkalizing agent solutions are added to adjust the pH value of mixed liquor to 1.5 to 4.5, undissolved substances are filtered out, and the
chromium-contained retaining-filling agent is obtained, wherein the
solid content ranges from 40 percent to 45 percent, the content of
chromium sesquioxide ranges from 1.5 percent to 5 percent, and the pH value ranges from 1.5 to 4.5. According to the method, chromium and
skin collagen
protein in chrome leather scrap can be utilized at the same time, the prepared hromium-contained retaining-filling agent is more comprehensive in performance, and problems caused by an existing
chemical modification manner can be solved.