Biomass waste is a plentiful and sustainable resource, and the transformation of this waste into porous carbon materials through uncomplicated and energy-efficient processes has become a significant focus of current research. Acidic carbon materials rich in sulfonic acid (-SO3H), carboxylic acid (-COOH), and hydroxyl (-OH) groups are obtained by in-situ sulfonation or post-grafting sulfonation of biomass or amorphous carbon materials. All of the functional carbon materials incorporating -SO3H groups are referred to as sulfonated carbon. The unique surface structure of sulfonated carbon makes it have great application prospects in the areas of catalysis, energy storage, and environment. This review summarizes the research on the production of raw materials, preparation processes, reaction mechanisms and physicochemical characteristics of sulfonated carbon, describes the current applications of sulfonated carbon in various fields including solid acid catalysts, energy storage materials, adsorbents, soil improvement and carbon-based fertilizers, and points out the problems and challenges facing the application of sulfonated carbon. As the preparation technology for sulfonated carbon continues to improve, further exploration of its stability, selectivity, and wide applicability is necessary. As a highly promising new type of carbon material, sulfonated carbon is expected to have a wide range of applications in various fields.