Abstract: This study aims to optimize the immobilization conditions of alginate lyase AlgL17 from Microbulbifer sp.,exploring the efficient conditions. By using tannic acid functionalized Fe₃O₄ magnetic nanoparticles as carriers,optimization of the immobilization conditions of AlgL17 was carried out. The optimum reaction temperature and pH of the immobilized enzyme were determined,and then the immobilized enzyme was analyzed by using scanning electron microscope(SEM)and Fourier transform infrared spectroscopy(FTIR). The results showed that the optimized immobilization conditions for AlgL17 were enzyme amount of 2.7 U,carrier amount of 25 mg,immobilization time of 5 h. Optimal reaction conditions for immobilized enzyme were of 35℃ and pH8.5.SEM and FTIR analysis showed that alginate lyase AlgL17 was immobilized on the surface of the carrier. Alginate lyase AlgL17 was successfully immobilized on Fe₃O₄ magnetic nanoparticles. The immobilized alginate lyase AlgL17 has potential in the industrial applications.