Abstract: To explore the mechanical performance of the counter-rotating knife roller (a key component of tobacco stalk extractors and hereinafter referred to as the knife roller) in a new type of tobacco stalk extractor, and to ensure its safe and stable operation, the dynamic stability of the knife roller was verified through Ansys modal analysis and EDEM discrete element simulation. The results showed that the natural frequency distribution of the first six order vibration model of the knife roller for stalk extraction was within 234-311 Hz, with a difference rate of 97.5%-98.2% from the actual operating frequency of 5.67 Hz, which was higher than the safety threshold of 15%, indicating effective avoidance of resonance risks. By establishing a Hertz-Mindlin bonding contact model to quantify the interactions between the knife roller and soil, an average soil cutting resistance of 1 187 N (peak value 2 124 N), an average torque of 247 N·m (peak value 514 N·m) and an average power dissipation of 3.9 kW (peak value 10.3 kW) were obtained. The difference between field trial data and simulation data was less than 10%, indicating the effectiveness of the simulation model. This study provides theoretical reference for promoting the safety and stability of tobacco stalk extractors.