Aiming to address the problem of high tillage resistance encountered by traditional rapeseed furrowing devices in the heavy clay soils of the Yunnan hilly and mountainous regions, a rapeseed furrowing device was designed based on plow body oscillation for drag reduction. A double-moldboard plow with lower resistance was selected as the furrowing plow based on the furrow profile. The maximum oscillation angle of the plow body was determined based on Coulomb's soil pressure theory and the geometric relationship between the plow body oscillation angle and furrow width. Mechanical principles and graphical methods were used to determine the dimensions of the mechanism components and verify its transmission feasibility. Finally, through motion analysis of the oscillating mechanism, the relationship between oscillation frequency and plow body motion performance was clarified. To determine the influence of different operating parameters on the drag reduction performance of the oscillating furrowing plow, identify the suitable operating parameter range, and determine the optimal operating parameters, single-factor and Box-Behnken simulation experiments were conducted using EDEM, with plow body oscillation angle, frequency, and operating speed as experimental factors and traction resistance as the evaluation index. Single-factor experimental results showed that the suitable operating speed of the device was 0.5~0.75 m/s, the oscillation frequency was 6~8 Hz, and the plow body oscillation angle was 8°~9.5°. Box-Behnken experimental results showed that the optimal operating parameters of the device were an operating speed of 0.50 m/s, an oscillation frequency of 7.98 Hz, and an oscillation angle of 8.1°. Field verification test results showed that, under the optimal parameter combination, the average traction resistance of the device was 1021.03 N, a 19.00% reduction compared with the traditional fixed-assembly plow body (1260.73 N), with an error of 3.9% compared with the simulation prediction. The furrow depth stability coefficient and furrow width stability coefficient were no less than 93.8%. The oscillating furrowing device showed significant drag reduction effects and stable furrow formation, providing a reference for the optimized design of furrowing devices.