A novel carbon based strong acid catalyst has been synthesized through the sulfonation of the carbon materials from glucose. The novel acid catalyst was obtained through the hydrothermal carbonization instead of the traditional heat treatment, which made the carbonization process under much milder condition with higher yield. The novel heterogeneous catalyst owned the advantages of high acidity as much as 2.0 mmol/g, much higher than that of Nafion and Amberlyst-15 (0.8 mmol/g). The catalytic activities of the catalyst were investigated through the acetalization. The results showed that the novel catalyst was very efficient for the reaction. The novel carbon based acid catalyst holds great potential in the green chemical process.