The invention relates to a method for simultaneously preparing multilevel-structure mesoporous silicon dioxide and a carbon nano material, belonging to the field of mesoporous nano material preparation. The method comprises the following steps: mixing water and alcohols to prepare a reaction solvent; adding a catalyst alkali, a reaction reagent resorcin and a surfactant CTAB (cetyltrimethylammonium bromide) into the reaction solvent; after stirring, adding a reaction reagent formaldehyde solution and TEOS (tetraethyl orthosilicate) to obtain a mixed solution; continuing stirring the mixed solution at room temperature, removing the supernatant to obtain a precipitate, and drying to obtain solid powder; calcining the solid powder at high temperature under inert gas shielding to carbonize the solid powder, thereby obtaining black solid powder; soaking the black solid powder in a hydrogen fluoride water solution or strongly alkaline solution to remove silicon dioxide, thereby obtaining a multilevel-structure mesoporous carbon material; and calcining the solid powder or black solid powder at high temperature in the air to obtain the multilevel-structure mesoporous silicon dioxide material. The method provided by the invention is simple to operate, has the advantage of low cost, and can implement large-scale production.