A dehydrogenation reaction system for a liquid hydrogen source material includes a storage device used for storing a liquid hydrogen source material and a liquid hydrogen storage carrier, a reaction still for dehydrogenation of the liquid hydrogen source material, a gas-liquid separator for separating the products, hydrogen and liquid hydrogen storage carrier which are generated after dehydrogenation of the liquid hydrogen source material, a buffer tank used for storing hydrogen, and a heating device used for heating the reaction still. The liquid hydrogen source material is input into the reaction still by means of a pump through an input pipe, dehydrogenation reaction of the liquid hydrogen source material is conducted in the reaction still, generated hydrogen is conveyed to the buffer tank, and the liquid hydrogen storage carrier generated after dehydrogenation is conveyed back to the storage device.