The invention provides a preparation method for preparing sulfonated graphene solid acid and a process for producing 5-hydroxymethyl furfural through catalyzing fructose. By automatically synthesizing a sulfonated graphene solid acid catalyst, fructose can be effectively catalyzed to dehydrate to produce the 5-hydroxymethyl furfural. Compared with a traditional process, the method for preparing sulfonated graphene, which is provided by the invention, is simple and high in preparation efficiency. Meanwhile, the process provided by the invention can be used for catalyzing high-concentration fructose to convert into the 5-hydroxymethyl furfural by using low-dose sulfonated graphene solid acid, the conversion efficiency is high, and the economic feasibility of 5-hydroxymethyl furfural production is improved.