The invention relates to the technical field of food processing with agricultural products as raw materials, and particularly discloses a preparation method of a fingered citron fruit juice beverage. Various factors limiting a fingered citron fruit juice beverage preparation procedure are comprehensively considered in the method, and a fruit juice beverage preparation process aiming at fingered citron fruit nutrition composition characteristics is purposefully studied. In the process, comprehensive studies on influence of a color protection technology, a composite enzymatic hydrolysis technology, a debittering technology, a blending technology and an ultra-high pressure sterilization technology on color, luster, flavor, taste and nutrition of the juice beverage are carried out, finally, a set of fingered citron fruit juice beverage preparation method which has the advantages of simple operation steps, mild process conditions, simple equipment and low cost, and is suitable for industrial popularization and large-scale production is obtained. Moreover, through comprehensive optimization of the formulation and the key process, the high-quality fingered citron fruit juice having natural color and luster, strong fragrance, nutrition and health can be prepared.