Aiming at the disadvantages of the present traditional silage of green or semi-green corn stalk powder, the compactness of lapping and pressing is small, the degree of anaerobic is not enough, the ammoniation is not good, there are some rotten and deteriorated, and it is inconvenient to seal in the process of opening and using. The key part of the high compression ratio packer, compression devices is designed. The compression molding experiments of four times, five times and six times compression ratio were carried out for the key component compression device in advance. The optimal compression ratio of 1:6 was determined through orthogonal design and multi-level analysis. Based on the quality purpose of improving packaging forming rate, the compression box is used by two hydraulic cylinders to open and close the feeding movable cover plate, two main hydraulic cylinders to compress the pressure, one hydraulic cylinder to push out and the pressure maintaining box to complete the compression and pressure maintaining forming. According to the properties of material expansion and springbackdue to stress relaxation after compression,the design experiment was carried out.the length of the pressure maintaining box is 600mm, the width is 300mm and the height is 365mm. After design and inspection the internal effective working range of the compression device is 1800mm in length, 600mm in width and 365mm in height,and the volume compression reaches a high compression ratio of 1:6, the anaerobic conditions is improved, the degree of ammoniation is improved and the use is more convenient.