Abstract: Taking the crust leather fiber tanned by TWS as the experimental object, the retanning treatment was carried out with chrome powder and TWLZ tanning agent respectively. Firstly, with the help of the Zeta potential analyzer and the thermogravimetric analysis, the influence of two retanning methods on the isoelectric point (pI) and thermal stability of TWS tanned leather fibers was systematically investigated; secondly, the adsorption difference of wattle extract on TWS tanned leather fiber was studied by adsorption experiment. The results show that the isoelectric point of crust leather fiber increased by 1.1 after chrome retanning and 1.8 after TWLZ retanning. Both retanning treatments can significantly increase the surface electropositivity of TWS tanned leather fiber, and the thermal stability of the crust leather fiber is also improved to varying degrees. The adsorption processes of TWS tanned leather fiber and its corresponding chrome retanning and TWLZ retanning leather fiber to wattle extract conforms to the quasi-second-order kinetic equation and Freundlich equation isothermal model. The retanning treatment can obviously improve the adsorption property of TWS tanned leather fiber to wattle extract, and the adsorption rules of the two retanning leather fibers are basically similar. It shows that TWLZ tanned leather has good compatibility with tannin extract materials suitable for chrome tanned leather, and the research results can provide certain theoretical support for chrome-free tanned leather in retanning and filling process with tannin extract.