Keywords Host-guest cage structured; MNPs@ALG@SiO.sub.2 composite; Embedding immobilized enzyme; Degradation of TeCG Highlights * Cage structure of MNPs @ ALG@SiO.sub.2 as enzyme carrier was synthesized. * The synthetic cage structure has high performance for the degradation of tetrachloroguaiacol. * Optimized the conditions for the degradation of tetrachloroguaiacol by magnetic composite cage structure. * The degradation mechanism were studied in detail. Entrapment of enzyme in a cage structure of alginate/silica composite gel can maintain the chemical or configurational structures unchanged in the enzyme, providing a promising means of enzyme immobilization. The alginate/silica composite gel can also provide more adsorption sites for the substrate, which is biocompatible and will carry out degradation and adsorption of pollutants within a cage-like structure reactor simultaneously. In this study, we used a magnetic host-guest cage structured MNPs@ALG@SiO.sub.2 composite with a specific enzyme embedded as its guest in the host matrix, to enhance its performance. Additionally, its swelling, leakage rate and immobilization conditions were optimized. The magnetic nanoparticles (MNPs) were used to compensate for the ease of collapse of the internal structure of alginic acid, while SiO.sub.2 was used to enhance the swelling resistance of the carrier and prevent the degradation of polysaccharides in the natural environment, thereby maintaining the enzyme biological activity and immobilization rate. Finally, the effects on the degradation of tetrachloroguaiacol (TeCG) by the immobilized enzyme embedded in the MNPs@ALG@SiO.sub.2 composite were investigated. When the concentration of ALG was 2% and the TEOS concentration was 40 %, the immobilized MNPs@ALG@SiO.sub.2 was found to perform the best. The optimum conditions of immobilizing laccase are pH = 5, enzyme concentration 0.4 g/L, adsorption time 12 h and temperature 20 a. The degradation conditions of TeCG are pH = 6, degradation temperature 40 a, degradation time 10 h and the degradation products of TeCG were acetic acid and ethanol according to GC--MS. Author Affiliation: (a) School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China (b) State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (Chengdu University of Technology), Chengdu, 610059, China (c) Department of Materials Science and Engineering, University of Delaware, DE, 19716, USA (d) State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, 130012, China * Corresponding author at: School of Chemistry and Molecular Engineering, East China University of Science & Technology, Shanghai, 200237, China. Article History: Received 3 September 2020; Revised 9 December 2020; Accepted 30 December 2020 Byline: Jie Li (a), Yuxiang Yang yxyang@ecust.edu.cn (a,c), Zhiyong Han (b), Min Zhao (a), Hongming Yuan (d), Chaoying Ni cni@udel.edu (c)