With the development of agricultural modernization, accelerating agricultural mechanization has become an important direction for the development of agriculture in China. However, agricultural mechanization is uneven and insufficient in terms of regions, industries, crop varieties, and production stages. Although there are already a large number of agricultural machinery products on the market, most of them are designed for large-scale crops in northern arid lands, lacking machinery suitable for barley and adaptable to small plots and sloping farmlands in the Qinghai-Tibet Plateau region. The development of a barley harvester adapted to plateau mountainous areas contributes to the development of special agricultural machinery in China, improves the uneven development of agricultural mechanization, and promotes agricultural development in plateau mountainous areas. This paper conducts research on the actual terrain of the Qinghai-Tibet Plateau, barley planting conditions, and harvester operational conditions. Based on the production needs of barley agriculture, the design is optimized and improved. Following the principle of overall coordination, the overall structural parameters of the harvester suitable for the operational requirements of plateau mountainous areas are determined. The structural design of key components such as wheelbase, axle spacing, ground clearance, harvesting mechanical arm, and harvesting mechanism is detailed. Additionally, SolidWorks software is used for three-dimensional modeling of the barley harvester. CAE technology is employed to analyze the static and dynamic performance of critical chassis components, validate theoretical calculations, and confirm final structural parameters. Furthermore, a dynamics characteristic model is established based on the optimized parameters to theoretically analyze the stability of the entire machine and verify whether the designed plateau barley harvester meets field operation requirements. Finally, Bluetooth communication technology is utilized to autonomously design control hardware and software, achieving intelligent control of the machinery.