The invention relates to a melting and cocrystallization method of erythritol and a high-power sweetening agent and a product obtained by the melting and cocrystallization method. The cocrystallization method comprises the following steps of (1) preparing an erythritol solution; (2) adding the high-power sweetening agent to the erythritol solution so as to obtain erythritol-high-power sweetening agent mixed liquor; and (3) sufficiently stirring the erythritol-high-power sweetening agent mixed liquor for 20-40min, and then quickly reducing the temperature so as to obtain an erythritol-high-power sweetening agent cocrystallization body. The erythritol-high-power sweetening agent cocrystallization body prepared by the cocrystallization method disclosed by the invention not only reserves the original nature of the erythritol being low in calorific value, resistant to decayed teeth and suitable for diabetics, but also has the advantages of being quick to dissolve, homogeneous in sugariness,long in quality guarantee period and the like; and besides, the method disclosed by the invention is simple to operate and low in cost and is suitable for large-scale industrial production.