To mitigate the high stubble rates (root residue rates) and plant damage associated with the current mechanized harvesting of Shanghai Green (Brassica rapa subsp. chinensis), this study developed and optimized a novel soil loosening and root lifting device. A theoretical dynamic model was first established to analyze the device’s operational principles. Subsequently, a coupled multi-body dynamics and discrete element method (RecurDyn-EDEM) model was established to simulate the complex interactions between the device, soil, and plant roots. Response surface methodology was employed to optimize key operational parameters: walking speed, loosening depth, and vibration frequency. The simulation-based optimization was validated by field tests. The optimal parameters were identified as a walking speed of 0.137 m/s, a loosening depth of 34.5 mm, and a vibration frequency of 1.34 Hz, under which the Shanghai Green pulling force was 35.41 N, yielding optimal extraction performance. Field tests conducted under these optimal conditions demonstrated excellent performance, achieving a qualified plant posture rate of 87.5% and a low damage rate of 7.5%. This research provides a robust design and validated operational parameters, offering significant technical support for the development of low-loss harvesting equipment for leafy vegetables.

To improve the harvesting efficiency of mechanized cabbage harvesting and reduce damage, the structural configuration of a cabbage harvester was designed based on the cabbage cultivation pattern, physical morphological parameters, and mechanical harvesting characteristics. The harvester consists of a crawler power chassis, pulling device, crop guiding device, clamping and conveying device, profiling device, root-cutting device, and leaf-stripping and collecting device, which enables simultaneous pulling, conveying, root cutting, outer leaf separation, and collection for two rows of cabbages in a single pass, thereby enhancing harvesting efficiency. The sources of cabbage damage during the harvesting process were analyzed, and dynamic analyses of the key components were performed to determine their structural parameters. Through single-factor experiments and response surface methodology optimization tests, the effects of forward speed, pulling roller rotational speed, clamping and conveying speed, and cutter rotational speed on the harvest qualification rate were evaluated. The optimal working parameter combination of these factors was determined and validated through field harvesting performance tests. The results showed that, under the operating conditions of forward speed 0.4 m/s, pulling roller rotational speed 114 r/min, clamping and conveying speed 0.51 m/s, and cutter rotational speed 338 r/min, the average harvest qualification rate reached 96.4%, and the average damage rate was 3.6%, which is close to the maximum theoretical harvest qualification rate of 96.78% predicted by the optimization model. The field validation tests demonstrated good performance, with all indicators meeting the design requirements and relevant standards, providing theoretical support and reference for the development and improvement of cabbage harvesting machinery.