In order to improve the harvest efficiency of green onion, a new type of green onion harvester mining system with high efficiency and low resistance was designed by combining the planting mode of green onion with the existing technology. Compared with the common excavator, the combined excavator is composed of two twisted dragons with opposite rotating directions, a second‐order excavator and a hydraulic adjusting device. The Angle and depth of the excavator can be adjusted to make it reach the optimal working state. Through the construction of the mathematical model of mining resistance, the mathematical model of mining resistance is obtained, and the influence of various parameters on the excavation of green onion is studied successively, so as to improve the design parameters and optimize the structure.