The invention discloses an automatic aquatic feed feeding device. The automatic aquatic feed feeding device comprises a base, two shells and a rotary feeding device. The base is of a cuboid structure, and two arch-shaped pits in parallel are formed in the upper end face of the base. Each shell is provided with a first long-strip-shaped arc groove with an upward opening, the bottoms of the two shells are embedded into the arch-shaped pits respectively, the two adjacent side walls of the two shells are first side walls, and the remaining side walls of the two shells are second side walls. The rotary feeding device comprises two supporting rods, two rotating parts and multiple feeding parts, wherein the lower ends of the two supporting rods extend downwards into the middles of the first grooves of the two shells respectively, and rod bodies of the two supporting rods but against the two second side walls; the two rotating parts are of a cross structure formed by crossing two rotary arms; each feeding part is of a funnel-shaped structure, the side wall of the feeding part and the two ends of the two rotary arms are fixedly arranged, and the big-opening end of each feeding part faces the rotating direction of the rotating parts. The automatic aquatic feed feeding device is high in feeding speed and saves labor resources substantially.