Aiming at the problem of poor corn kernel crushing effect and low crushing rate of corn silage corn harvester, which affects the fermentation of silage straw and the conversion of kernel nutrients, combined with the disc-type kernel crushing technology which has the advantages of high working efficiency and good crushing quality, a dish-type silage corn kernel crushing test bench suitable for crushing silage corn kernels was developed. Parametric design of the key components of the cutter head, the movement and mechanical analysis of the grain crushing process were done based on the DEM method, firstly, the corn kernel bonding particle model was established based on the discrete element method. The EDEM discrete element simulation software was used to carry out the optimization simulation of the orthogonal experiment. The number of teeth, depth of blade, crushing gap and speed of the cutter roll were selected as the simulation test factors. The grain crushing rate was tested and investigated. The optimal combination parameter was determined: the number of teeth was 48, the depth of blade was 5mm, the crushing gap was 2mm, and the speed of the knife roll was 59r/s. Under these conditions, the grain crushing rate was 90.35%, and the relative error between the simulation test and the bench test result was 3.36%. After the end of the bench test, the materials were screened with a Pennsylvania screen. The materials can be divided into four types: small, standard, large and incompletely crushed, with a ratio of 1.3∶6∶1.8∶0.9, which was consistent with the simulation test results. The various indicators of the bench test met the industry standards, achieving high crushing of corn kernels and high working efficiency.