Abstract: A composite nanoparticle hollow mesoporous SiO₂(HMSiO₂)@chitosan-graft-polyamidoxime(CTS-g-PAO) was prepared via HMSiO₂ through sol-gel method used as CTS coating on HMSiO₂ by inverse microemulsion synthesis used as the matrix to graft polyacrylonitrile (PAN), which was transformed to PAO. The component and the structure of the HMSiO₂@CTS-g-PAO composite were examined by FTIR and XRD. The morphology and the size of the HMSiO₂@CTS-g-PAO were confirmed by SEM and Laser Particle Size Analyzer. The results show that the HMSiO₂@CTS-g-PAO is core-shell nanoparticle with the HMSiO₂ as the core and the CTS-g-PAO as the shell. K₂Cr₂O₇ solution is used as the Cr target for detecting the adsorption capacity of the prepared HMSiO₂@CTS-g-PAO. The results indicate that the adsorption capacity of Cr^VI is 3.28 mmol/g when the pH of K₂Cr₂O₇ solution is 2 and the concentration of the solution is 91.4 mg/L. Furthermore, the adsorption process is consistent with the pseudo-second-order kinetics and mainly belongs to chemical adsorption.