A plant processing system of the present invention includes: a plant cultivation facility (1) which cultivates plants including a sugar solution； a crushing facility (2) which crushes plants felled in the plant cultivation facility (1)； a juicing facility (3) which harvests sap from plant chips obtained by the crushing facility (2)； a methane fermentation facility (5) which performs a methane fermentation process on the sap； and a power generation facility (6) which generates electric power using a biogas obtained by the methane fermentation facility (5) as a fuel.
