Abstract: This work focused on the problem of high arsenic (As) residues in kelp polysaccharides and develops an effective method for removing As from kelp polysaccharides. Lavoisier Frameworks material (MIL-88A) was assembled with Polyurethane foam (PU). Scanning electron microscopy (SEM), Fourier infrared spectroscopy (FTIR), and X-ray diffraction spectroscopy (XRD) were used to characterize the morphology and surface functional group of MIL-88A/PU materials, and then atomic fluorescence spectroscopy (AFS) was used to investigate the ability of MIL-88A/PU to remove As. Results showed that MIL-88A was successfully loaded on PU, and the MIL-88A/PU possesses abundant active sites. The maximum adsorption capacity for As (III) was 107.52 mg/g when the absorption conditions maintained at 298 K, pH5.0, and 240 min. After treating by MIL-88A/PU, the amount of As in kelp polysaccharides were effectively reduced, and the removal rate of total As and inorganic As was 70.43% and 73.33%, respectively. Moreover, the preservation rates of polysaccharide and protein content in kelp polysaccharides were 90.47% and 73.76%, respectively. Remarkably, dealing kelp polysaccharides with MIL-88A/PU significantly reduced the amount of As, which would improve the economic benefit of the kelp polysaccharides.