The invention provides a preparation method for enhancement type silicon-carbon framework biomass aerogel. The preparation method comprises the following steps: 1, cleaning and cutting peel of cucurbitaceous plants into blocks, putting the blocks into a reaction kettle with a polytetrafluoroethylene lining, adding distilled water into the reactor, carrying out constant-temperature thermal reaction, and obtaining biomass carbon-based wet gel after the reaction is ended; 2, preparing a mixed solution A of tetraethyl orthosilicate and alcohol, completely putting the biomass carbon-based wet gel obtained in the step 1 into the mixed solution A to soak; 3, cleaning a product soaked in the step 2; 4, washing the product cleaned in the step 3 with acetonitrile in a water bath; and 5, drying a product obtained by washing in the step 4 in a vacuum drying box, thereby obtaining a final product, namely the enhancement type silicon-carbon framework biomass aerogel. According to the preparation method, a surfactant or a template agent is not needed to be added, and normal-pressure drying is adopted, so that the production cost is reduced; and the prepared material is low in density, is great in specific surface area, and has relatively good discoloring effect and relatively good dye adsorbing effect.