Abstract: In order to improve the harvest efficiency of landing jujubes, a jujube harvester with air suction picking as the core was designed. Through the determination of the material characteristics of jujube and the physical characteristics of the debris in the harvest, as well as the analysis of the bending state of the suction pipe in the harvest process; EDEM software was used to establish the suction pipe, jujube and main sundry objects model, combined with ANSYS Flunt software to carry out fluid-structure coupling simulation of material movement in the suction pipe under the maximum and minimum bending state. Taking the impurity rate and the clean rate as the evaluation index, and controlling the other factors that affect the performance of the machine and tools, the comparative test of the maximum and minimum bending state of the suction pipe is made.The simulation results show that the maximum speed of materials under the maximum and minimum bending conditions of the pipeline is close to 10 m/s and 8 m/s respectively. The comparison test results show that the average difference of impurity content under the maximum and minimum bending conditions of the pipeline is 0.15% and the difference of cleaning rate is 0.27%.Through the analysis of the simulation results and the comparative test results, it is concluded that the bending state of the selected suction pipe has little influence on the performance of the machine.