Preparation method of carbon-based sulfoacid solid acid catalyst

The invention discloses a preparation method of a carbon-based sulfoacid solid acid catalyst, and relates to a preparation method of an acid catalyst. The preparation method provided by the invention can solve the technical problems that a conventional method for preparing the carbon-based sulfoacid solid acid catalyst is long in synthesis time, high in energy consumption and high in price. The method provided by the invention comprises the following steps of: firstly, adding absolute ethyl alcohol into a raw material, uniformly stirring the absolute ethyl alcohol, and then adding concentrated sulfuric acid the mass concentration of which is 98%, thus obtaining a mixture; secondly, heating and stirring the mixture which is obtained in the step 1, carrying out natural cooling on the mixture, adding the mixture into distilled water, stirring, standing and filtering, then, washing until sulfate ions do not exist in a filter liquor, and drying, thus obtaining the carbon-based sulfoacid solid acid catalyst. The preparation method provided by the invention has the advantages that the price of raw material is low, a preparation technology is simple, the condition is mild, the cost is low, the synthesis time is short, the prepared carbon-based sulfoacid solid acid catalyst has the good catalytic activity and the high stability, and the activity is still more than 80% after three times of circulated use. The preparation method provided by the invention is applied in the preparation field of catalysts.