An organic/inorganic hybrid mesoporous silica membrane (HMSM) composed of mesoporous silica rods in the channels of a polycarbonate (PC) membrane was rapidly synthesized by employing the microwave-assisted method combined with solvent extraction. As-synthesized HMSMs were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), N₂ adsorption–desorption, X-ray diffraction (XRD) and thermogravimetry (TG). The results indicated that silica rods with 200 nm diameter and 9 μm length grew in the confined spaces of the PC membrane. The average diameter of mesopores with partially ordered hexagonal mesostructure was about 6.0 nm. In addition, it was found that an enzyme with suitable size, such as horseradish peroxidase (HRP), could be immobilized inside the mesopores of HMSM through physical adsorption. Moreover, an electrode modified by HMSM with adsorbed HRP exhibits excellent direct electrochemical behavior of HRP and electrocatalytic effect toward H₂O₂, and can be further potentially applied in biosensors.