Aiming at the problems of serious slippage, poor uniformity and poor crop adaptability of the existing flatbed straight blade chopping tool, based on the functional and structural characteristics of beaver’s lower incisors, the skull model of beaver was extracted and the characteristic curves of the lower incisors was fitted by adopting the three-dimensional laser scanning and computer-assisted processing of the inverse engineering technology, and then a kind of biomimetic silage forage chopping blade was designed according to the model. On the basis of constructing the bionic coupling structural characterization model of beaver lower incisor, the movement and force relationship between the clamp angle, wedge angle and slip angle of the lower incisor and the biological cutting behavior were determined through theoretical analysis, and the models of slanting cut and stable slip cut of the blade were established to derive the structural characteristics of the beaver’s lower incisor in the process of stabilizing the cutting process, and the mechanism of response to the resistance and slip reduction, and the model of the cutting force of the invasive material was established for the theoretical analysis of the cutting head force characteristics, and the model of the cutter head was used for the theoretical analysis of the cutter head force characteristics, and the model of the cutting force was used for the theoretical analysis of the cutter head. The theoretical analysis of the cutter head force characteristics was carried out, and the influence law of wedge angle and cutter head force and strength was obtained. The functional structure of beaver lower incisors was characterized in segments, and the blade shape was designed accordingly. In order to determine the optimal structural parameters of the blade shape, a four-factor, five-level orthogonal test was conducted to investigate the effects of the key parameters of the blade shape on the chopping effect of silage forage, using the standard grass length rate, slant stubble rate and broken pitch rate as the test indexes. The results of the bench test showed that when the clamp angle was 46°, the inner slip angle was 31°, the outer slip angle was 67° and the wedge angle was 28°, the standard grass length rate was 9584%, the slant stubble rate was 2.84%, and the broken knot rate was 95.46%. Under the optimal structural parameters determined in the bench test, the field harvesting validation test was carried out on ryegrass, whole silage corn and sweet sorghum respectively with the standard grass length rate, slant stubble rate and broken node rate as the test indexes, and the test results showed that when the operating parameters were 6km/h and the feeding rate was 8kg/s, the average standard grass length rate of ryegrass was 91.95%, the average slant stubble rate was 3.31%, and the average breaking rate was 96.11%;whole plant silage corn average standard grass length rate was 95.62%, the average slash stubble rate was 3.81%, the average breaking rate was 96.32%;sweet sorghum average standard grass length rate was 92.60%, the average slash stubble rate was 4.06%, the average breaking rate was 96.03%, the performance indexes were consistent with the national industry standards. The bionic chopping curved blade can cut smoothly and cut sections evenly, which had strong crop adaptability.