Abstract: Sodium alginate gel (SA) material has problems such as unsatisfactory treatment effect and low utilization rate in the treatment of chromium-containing wastewater. In order to solve these problems, sodium alginate was used as raw material, and gel balls (SA-Ba) were prepared by gel embedding method loaded with Ba²⁺, and polyethylene glycol was added for covalent mixing and modification to obtain polyethylene glycol modified barium alginate gel material (PEG-SA-Ba). Compared with the traditional calcium alginate (SA-Ca) gel ball, the chromium removal effect of the three gel ball materials and the effects of experimental parameters such as pH, initial Cr(Ⅵ) concentration, and PEG-SA-Ba dosage on the chromium removal effect of PEG-SA-Ba materials were investigated, and the samples were characterized by scanning electron microscopy (SEM) and Fourier infrared spectroscopy (FTIR). The results showed that: SA-Ba crosslinked with sodium alginate and Ba²⁺ greatly improved the chromium removal effect of SA, and the chromium removal amount was more than 800 times that of SA-Ca; the covalently modified PEG-SA-Ba provided more active sites for the adsorption of Cr(Ⅵ), and the chromium removal capacity was increased by 4.38 mg/g compared with that without modification. With the increase of pH, the removal rate of Cr(Ⅵ) by PEG-SA-Ba also continued to increase; the chromium removal capacity at pH 6 was 16.24 mg/g higher than that at pH 2, and when pH exceeds 8, the structure of the gel ball was unstable and easy to cause ion leakage, resulting in precipitate formation outside the gel ball. The chromium removal capacity of PEG-SA-Ba increased with the increase of Cr(Ⅵ) concentration and decreased with the increase of dosage. SEM and FTIR characterization verified that the Ba²⁺ loading was successful and the crosslinking effect of polyethylene glycol and sodium alginate was good. Finally, the discussion found that PEG-SA-BA gel ball materials had obvious advantages in preparation cost and method, saving more than 99% and 24% of material costs compared with SA and SA-Ba, respectively.