The invention relates to a fixing and supporting device for preparation of an ornamental fish specimen. The device comprises a base seat support and a fish body fixing tank arranged on the base seat support; the fish body fixing tank has a semi-rugby structure, and a plurality of fixing seats are arranged on the fish body fixing tank; and each fixing seat is provided with one supporting rod, one end of each supporting rod is connected to one corresponding fixing seat, and the other end is connected with one functional component through one elastic component, wherein the functional components are rubber air suction balls for opening fish mouths or fixing clamps for fixing pectoral fins, pelvic fins, dorsal fins, anal fins and caudal fins of ornamental fish. The fixing and supporting devicefor the preparation of the ornamental fish specimen provided by the invention solves the technical problems that when a fish specimen is prepared, a posture of the ornamental fish is difficult to maintain stably for a long time, multi-person cooperation is needed, time and labor are consumed, and efficiency is low, thereby effectively improving preparation efficiency of the fish whole specimen.