The invention relates to a method for synthesizing a cationic glucosamine surfactant, and belongs to the technical field of chemistry. The method comprises the following steps of: a, performing a free reaction; and b, performing a quaternary ammonium reaction. The method has the advantages that: side reactions are fewer, and the purity of products is high; undissolved substances such as inorganicsalts and the like are available to remove by taking sodium alcoholate as a free agent and corresponding alcohol as solvent, and the content of the product is improved; and the reaction condition is mild, the step is simple, and the method is favorable for large-scale industrial production.