In the paper, the necessity of root stubble harvesting and recycling was put forward from the perspective of biomass energy utilization. To accomplish mechanized harvesting on root stubble, a rotary digging machine was designed based on parametric modeling software Solidworks. Firstly, parts were built under entity modeling module, and then assembled to 4 main mechanisms in assembling environment. Secondly, mechanisms including frame, transmission mechanism, suspension mechanism and digging mechanism were assembled together to establish the whole prototype on which interference checking was done. Through manual change of the transmission chain’s installation position, the digging mechanism was able to shift between reverse and forward rotation according to different soil conditions. Finally, relevant 2-D engineering drawings were generated for manufacture. The paper provides methodological reference for the design of similar machines and preparation for further simulation and analysis of the designed models.