A straw fodder dewatering device comprises a machine body, wherein support columns and a conveying belt are sequentially arranged at the bottom of an inner cavity of the machine body from left to right, an electric push rod is fixedly connected with one side of the inner cavity of the machine body, a push plate is fixedly connected with one end of the electric push rod, a dewatering plate is fixedly connected with the tops of the support columns, and a dewatering device located in the machine body is arranged over the dewatering plate. The straw fodder dewatering device is provided with the dewatering device and the dewatering plate, an operator places to-be-processed straw on the dewatering plate, a connecting block at the bottom of hydraulic rods is driven by hydraulic cylinders to stretch and retract vertically, so that bulges at the bottom of an extrusion plate are driven to move up and down, extrusion dewatering of the straw on the dewatering plate is realized, automatic extrusiondewatering of the straw is realized, the dewatering efficiency is improved, dewatering is performed in the machine body, pollution to the cleaned straw due to airing is avoided, and the fodder quality is guaranteed.