The invention discloses a biodegradable low-surface-energy graphene marine antifouling anticorrosion coating material, and a preparation method thereof. The preparation method comprises following steps: 1, natural crystalline flake graphite is taken as a raw material, and modified Hummers method is adopted to prepare hydroxy graphene; 2, ring-opening polymerisation is adopted to prepare graphene-grafted polycaprolactone; 3, a graphene-grafted polycaprolactone high molecular initiator is synthesized; and 4, ATRP technology is adopted to prepare the biodegradable low-surface-energy graphene marine antifouling anticorrosion coating material. The biodegradable low-surface-energy graphene marine antifouling anticorrosion coating material possesses both low surface energy and degradable performance, and excellent antifouling effect; combination with graphene core is capable of improving coating corrosion resistance and achieving excellent mechanical properties; the biodegradable low-surface-energy graphene marine antifouling anticorrosion coating material possesses seawater corrosion resistance; degraded products are nontoxic, and are friendly to the environment; functional modification of graphene is capable of improving the compatibility of graphene; and application prospect in the fields such as ship antifouling anticorrosion and offshore oil platform antifouling anticorrosion is promising.