Abstract: In order to solve problems of low efficiency and high cost of Codonopsis pilosula manual excavation, a four-bar mechanism Codonopsis pilosula excavation device was designed based on human simulation．Simplified model of soil- Codonopsis pilosula excavation device was established by means of Proe, simplified model of soil- Codonopsis pilosula - excavation device was established by means of discrete element simulation software EDEM and multi-body dynamics software Adams．Through ADAMS_ EDEM conducts simulation excavation experiments, range of rotational speed and soil entry angle was determined when resistance was low．SAS software was used to carry out optimum balance random design test for rotational speed and soil entry angle, and soil trench excavation test was verified．Simulation results showed that the better range of earth angle was from 75° to 80°．The optimum speed range was from 60 r/min to 90 r/min．Excavation test results showed that when the best combination was 70 r/min and 75° by final analysis, loosing rate of codonopsis pilosula was 97.94%, damage rate was 4.52%．The next was 60 r/min and 75°, loosening rate was 96.62% and damage rate was 5.7% ．