The invention relates to non-additive natural fructus momordicae syrup. The non-additive natural fructus momordicae syrup is prepared from a raw material adsorption resin wastewater which is producedduring production of fresh fructus momordicae, and the adsorption resin wastewater specifically comprises 14-24% of glucose, 16-24% of fructose, 1-14% of sucrose, 1-8% of mannitol, 40-50% of water andnot more than 2% of the remaining components. The preparation method of the non-additive natural fructus momordicae syrup comprises the steps: refining the adsorption resin wastewater produced duringthe production of fresh fructus momordicae, performing decolorization, deacidification and removal of pesticide residues and heavy metals, and performing concentration and other operation so as to obtain the non-additive natural fructus momordicae syrup. No additives except fructus momordicae, seed-free fructus momordicae and water are involved, and therefore the non-additive natural fructus momordicae syrup is natural non-additive fructus momordicae syrup. According to the preparation method, a good-taste flavor fructus momordicae beverage can be obtained effectively, and the non-additive natural fructus momordicae syrup can also be used as an additive in food, beverages, dairy products, health care products, drugs and other products; the preparation method is simple and easy, the obtained product has a high economic value, and environmental protection standards can be met by the discharged waste liquid without further treatment; and a comprehensive utilization method of the fructusmomordicae production wastewater is provided, and the preparation method has a high economic value, and is suitable for large-scale industrial promotion.