The invention provides a TiO2 nanotube composite SiO2 aerogel-based photocatalytic material and a preparation method thereof. The preparation method includes the steps of making titanium dioxide and a NaOH solution react to obtain reaction liquid, conducting centrifugal separation on the reaction liquid to obtain white sediment, regulating the pH value through acid under mixing, conducting washing till the pH value is neutral, conducting centrifugal separation to obtain lower layer sediment, conducting roasting after conducting drying, evenly mixing the lower layer sediment with a silica solution, conducting gelatinization under the stirring condition to obtain gel, aging the gel through absolute ethyl alcohol, and then conducting drying through low-temperature supercritical CO2. The prepared composite photocatalytic material has wide application prospects in the fields of photodecomposition hydrogen manufacturing, pollution treatment, surface antifouling and self-cleaning, and the like, and the prepared TiO2 nanotube composite SiO2 aerogel-based photocatalytic material is excellent in performance and has high photocatalytic activity and yield stability. The preparation method is simple, high in drying efficiency, small in man-made influence factor and low in cost.