Abstract: Ma yam is one of the most highly precious and popular cash crops, due to its nutritional and medicinal properties. However, the current harvesting of ma yam relies primarily on manual labor or semi-machinery. The special harvesting machinery has hindered the sustainable development of the ma yam planting industry. In this study, a vibratory soil crushing device was developed in a ma yam harvester, according to the agronomic practices and harvesting requirements of the cultivation. The ma yam harvester was connected to a tractor via a suspension device. The vibration soil crushing device was composed of an eccentric wheel, support plate, connecting plate, soil crushing plates, and soil crushing shovels, which were driven by the rear power take-off shaft of a tractor. The soil crushing plate and shovel were driven by the eccentric wheel to oscillate rhythmically, crush up the soil through vibration, and then separate the ma yam from the earth. The trenching device was also used for the deep trenches on either side of the ma yam plants during operation. The vibrations were applied to the soil surrounding the ma yam, thereby crushing it up and then exposing the roots. The trenching device was realized at a depth of 1 400 mm and a width of 100 mm, resulting in a central soil ridge as the 250 mm post-trenching. The soil crushing shovel was measured as 250 mm in width, with a grid length of 200 mm and a 20 mm spacing. The soil crushing plate was extended to 120 mm, with evenly distributed rectangular teeth. Each tooth was measured as 80 mm in length and 50 mm in width, with an 85° angle to the horizontal plane. A discrete element simulation was performed on the ma yam-soil-vibration soil crushing device using EDEM 2020 software. A systematic analysis was then carried out on the effects of the operating speed, vibration frequency, and vibration amplitude on the soil fragmentation and ma yam damage rates. The significance of each factor and their interactions was assessed using the response surface method in Design-Expert 13 software. The operating speed and vibration amplitude were obtained to significantly determine the rate of soil fragmentation. Specifically, the vibration amplitude also had an outstanding impact on the damage rate of the ma yam. A series of experiments was carried out to verify the optimal combination of the operating parameters. A better performance was achieved in an operating speed of 0.135 km/h, a vibration frequency of 8 Hz, and a vibration amplitude of 45 mm. A series of tests was carried out using a prototype in the experimental field in Baoding City, Hebei Province, China. The damage rate of ma yam also served as the primary evaluation index. The experimental factors included the operating speed of the machinery and the vibration amplitude of the soil crushing device. The soil type in the experimental field was characterized as sandy loam. The relative error of the damage rates between the field trial and the simulation was under 10%. The damage rate of ma yam was reduced to 8.47%, with the optimal combination of the operating parameters. The harvesting needs were fully met after optimization. This finding can also provide a technical framework for the harvesting machinery, particularly for the geophyte species with fragile root crops.