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In order to solve the problem that it is difficult for the passive anti-blocking device to take into account the cutting effect and the operation power consumption during no-tillage sowing of corn in Northeast China, a passive disc antiblocking device was designed based on the principle of dynamic sliding cutting characteristics of the sawtooth disc, which could effectively improve the straw cutting effect while fully applying the sliding cutting effect. According to the dynamic sliding cutting characteristics of the sawtooth disc, a dynamic sliding cutting and structure conversion model was constructed, and the sliding cutting characteristics of the sawtooth of corn straw under support cutting were carried out. The conclusion that the optimal dynamic sliding cutting angle under the sawtooth structure was 15°~30°, and the hypothesis of the influence of the sawtooth rake angle on the two types of cutting process was put forward for the two special cutting processes and load curves generated under the sawtooth structure, and it was verified by combining the soil groove test and the discrete element simulation experiments. The quadratic regression rotational orthogonal experiment was carried out to determine the optimal operating parameters of the sawtooth: the forward speed was 2.0m/s, the sawtooth rake angle was 21.3°, and the tooth height was 6.0mm. According to the simulation results, the disc processing was completed and the field experiment was carried out. The results showed that when the straw covering amount was 1.97kg/m2, the sawtooth disc straw cutting rate was 76.2%, the vertical peak downforce was 875.7N, and the average downforce was 544.1N, the sawtooth structure design of the planar disc was increased by 34.7 percentage points, and the peak downforce and average downforce were reduced by 5.7% and 7.9%. The disc operation performance was ideal, and it met the no-tillage sowing requirements in Northeast China, and can provide a theoretical reference for the research of cut-off anti-blocking device for no-tillage seeder.