The invention discloses a making method of green plum concentrated juice. The method includes the following steps that 70-80% maturity green plums are selected, washed, denucleated and pulped to be frozen, the freezing temperature is minus 8DEG C-minus 10 DEG C, and the freezing time is less than three months; 2, after frozen fruit juice is unfrozen, enzymolysis factors are added for enzymolysis, the enzymolysis temperature is 40-60 DEG C, and when the acidity of citric acid reaches 100 g/kg or above, solid-liquid separation is conducted; 3, separated juice is subjected to dehydration and concentration under the vacuum state with the pressure intensity smaller than -0.08 MPa, the concentration temperature is smaller than or equal to 80 DEG C, when the weight percentage of the moisture is lower than or equal to 5%, the juice is sterilized, and a finished product is obtained. The whole process is free of a high temperature, and energy consumption is lowered; the nutritional ingredients of the green plum are maintained to the maximum degree, and the absorption effect of an organism is better improved; the variety of organic acid of the green plum is increased and reaches one hundred and forty or more, and the effective ingredients of the green plum are utilized to the maximum degree; no toxic substance is generated or discharged in the processing process, and toxic metabolite generated by the organism is neutralized to the maximum degree.