A novel magnetic amino acid functionalized aluminum alginate gel polymer Gly/Al/SA@Fe₃O₄ was prepared via droplet polymerization technique with sodium alginate (SA) as raw material, which was crosslinked with Al(Ⅲ) ions, while glycine (Gly) and Fe₃O₄ were simultaneously added. The prepared Gly/Al/SA@Fe₃O₄ was characterized by means of scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (EDS), Fourier infrared spectroscopy (FT-IR), X-ray diffractometer (XRD) and vibrating sample magnetometer (VSM). Its absorption performance for azo dyes was also investigated. The results show that Gly/Al/SA@Fe₃O₄ is a kind of three-dimensional network-like polymer particles with a fancy fold structure on the surface, and its magnetic response ability is good. Gly/Al/SA@Fe₃O₄ shows strong adsorption performance with high adsorption rate for Direct Black 19(DB 19) and Direct Brown 2(DB 2) dyes in water. The dynamic equilibrium adsorption capacities reached 2500 mg/L and 3126 mg/L, respectively for the above two dyes in 15min and 60 min. The adsorption process can be described by a quasi-second-order rate equation, and the isothermal adsorption data conform to Langmuir model. The interaction between the adsorbents and dye molecules was synergistic through electrostatic adsorption, hydrogen bonding, ligand exchange and chemisorption. Gly/Al/SA@Fe₃O₄ particles are green and environment-friendly, and have strong water purification ability for wastewater containing high concentration azo dye, therefore, it can be used for rapid solid-liquid separation with magnetic field.