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The L. barbarum is a kind of infinite inflorescence berry plants, which means it must be picked once about every 7d and need to be harvested 12 times a year during its growing season. At present, the artificial picking L. barbarum has the disadvantages of low efficiency and high labor intensity. With the market demand of L. barbarum growing increasingly year by year, its planting acreage is expanding quickly, a great deal with fruit pickers are demanded. However, the number of people to be skilled at picking L. barbarum is less and less. Mechanization of L. barbarum picking device can improve production efficiency, save planting costs and promote the rapid development of L. barbarum industry, thus the realization of L. barbarum mechanical picking is necessary. The selective picking principle was based on different fruit diameters between the mature and immature fruit, relying on friction and impulse force between the finger and L. barbarum to pick off the mature fruit. The immature L. barbarum, flowers and leaves would pass through the gaps between two fingers. However, mature L. barbarum approximate ellipsoid flexible body, during the brushing process, L. barbarum was clamped between two fingers and could not free fall off, affecting the followup picking. Therefore, variable pacing controlling component was designed to solve this problem. Firstly, to obtain the most reasonable brush finger spacing at two different limit positions, a mathematical model of the structural parameters of the variable pacing controlling component was established, which was optimized by fmincon function in Matlab software, and provided reference for the design of other parts. Based on the natural and physical parameters of L. barbarum, the brush finger structure was designed. Its key component affected the harvesting effect. Its structural parameters included the length of the spring steel, the spacing of fingers and the diameter of the spring steel. The greatest impact on the picking effect was the motor speed, which was determined by single factor tests, and optimal range was under 30r/min. The test was conducted at planting base of L. barbarum of Ningxia Academy of Agriculture and Forestry Sciences, by measuring the picking rate and the damage rate of the prototype under different structural parameters of the brush finger. A theory reference was provided for design of combing brush device. The main parameter influencing the picking rate and damage rate of the picking finger was determined by orthogonal test method which included the length of the spring steel, the spacing of fingers and the diameter of the spring steel. And the optimal results showed that the best combination was A1B2C2 group of which the spacing of fingers was 8mm, the length of the spring steel was 45mm, and the diameter of the spring steel was 1.1mm. And the corresponding performance indexes were as follows: the picking rate reached 90%, yet the damage rate was only 8.41%. The results can provide a reference for the development of L. barbarum combing brush picking machines.