Encapsulation is demonstrated to be an effective method for enzyme immobilization. Compared to traditional methods，the biomimetic approach at mild conditions has garnered much interest. For the removing phenol in waste-water，silica formed by polyethyleneimine-inducer was used to immobilize horseradish peroxidase(HRP)at room temperature and neutral pH in this paper. The results of SEM show that immobilized HRP particles are near-spheres from 200 to 500 nm. FT-IR spectra indicate that HRP is successfully encapsulated within the silica matrix. The immobilized HRP can be of higher thermal，pH and storage stability. The electrostatic interaction between polyethyleneimine and HRP i.e. immobilization ratio of HRP is affected by type of solvent used. If phosphate buffer is employed as system solvent，immobilization ratio of HRP is 65.3% and activity ratio is 70.8%. The silica-encapsulated HRP obtained was used for removal of phenol，and maximum removal could reach 73.1%. After 5 repeated cycles，51.7% of initial activity is still retained.