Shaddock genus olive, secondary fruit pericarp comprehensive utilization and process technique

The present invention relates to a processing process for comprehensive utilization of pomelo green fruit, rejected fruit and fruit peel. Said processing process includes the following steps: using Na2CO3 solution whose mass ratio is 0.5% to wash green fruit or rejected fruit, using milling machine to mill green fruit or rejected fruit to obtain oil and water mixture, filtering and separating oil layer from water layer; pulverizing the residual fruit or pomelo fruit peel to 2-3mm, regulating pH value to 1-2, heating for 0.5-1.5hr at 85deg.C so as to obtain pectin solution; filtering pectin solution by using filter cloth, separating filtrate by using inorganic ceramic membrane, concentrating, adding proper quantity of distilled water to wash pectin concentrate to make its pH value be 2.6-3; spray-drying pectin concentrate directly to obtain powdered pectin product; making penetrating solution obtained after membrane separation be passed through macroporous adsorbing resin to recover pomelo flavone; then utilizing residue to make fermentation, adding nitrogen, phosphorus and potassium inorganic fertilizer to prepare organic-inorganic composite fertilizer.