Optimal Design and Testing of a Crawler-Type Flax Combine Harvester

China is a large flax-growing country, with planting area and production ranking among the top three in world. However, cultivation range of flax very broad, complex, diverse, resulting different scales patterns, making it difficult to apply foreign combine harvesters, lacks dedicated harvester. This research improved design 4LZ-4.0 crawler-type harvester for regional features cropping patterns China. First, structure, technical parameters, working principles machine were introduced; second, theoretical analysis optimization key components performed; finally, advancing speed machine, threshing drum, suction fan as independent variables rate removal total loss response values, three-factor, three-level surface method was used. For each component value, mathematical model created, factors their interactions evaluated confirmed. The results demonstrated that parameters impact drum speed, centrifugal order priority, well priority. machine’s optimal operating settings 1.5 m·s−1 788.49 r·min−1 885.34 validation test indicated under typical dryland dense mode, had 97.46% 2.99% after test. optimizing operational may decrease losses process mechanical harvesting, enhance harvesting efficiency, satisfy marketable standards.