The invention belongs to the technical field of denitration catalysts and particularly relates to a SiO2-containing denitration catalyst and a preparation method thereof. The denitration catalyst comprises the following components in percentage by mass: 1 to 2 percent of V2O5, 5 percent of WO3, 5 to 10 percent of SiO2 and the balance of TiO2. The preparation method of the denitration catalyst comprises the following steps of: preparing a TiO2-SiO2composite carrier by a co-precipitation method; loading V2O5 and WO3 by a one-step impregnation method; and obtaining the catalyst with high low-temperature denitration by roasting. The method has the characteristics of increasing the overall mechanical strength, wear resistance, and other performance of the catalyst; the silica solution used as a cheap silicon source for SiO2 can be well improved in mechanical performance in processing, extruding and forming processes.