针对新能源重型汽车低速重载、工况复杂的应用需求，本文以新能源重型汽车为研究对象，开展电驱动桥主减速器的优化设计。文章结合车辆低速重载、连续作业的工况特点，采用平行轴三级斜齿圆柱齿轮传动结构，完成减速增扭齿轮副的布局与关键参数优化设计。通过有限元强度仿真与台架试验相结合的方式，选取最大功率工况及倒车工况作为极限工况进行强度分析，并依据行业标准完成 30 万次疲劳耐久测试。结果表明，该主减速器的强度及耐久性能均满足使用要求，设计方案合理可靠，可为新能源重型汽车电驱动桥的自主研发与工程应用提供参考。

In response to the application requirements of low-speed heavy-load and complex working conditions of new energy heavy vehicles, this paper takes new energy heavy vehicles as the research object and conducts the optimization design of the main reducer gear of the electric drive axle. Considering the characteristics of low-speed heavy-load and continuous operation of the vehicle, a parallel-axis three-stage helical cylindrical gear transmission structure is adopted to complete the layout and key parameter optimization design of the reduction and torque-increasing gear pair. Through the combination of finite element strength simulation and bench test, the maximum power condition and reverse driving condition are selected as the extreme conditions for strength analysis, and 300000 fatigue durability tests are completed according to industry standards. The results show that the strength and durability performance of this main reduction gear meet the usage requirements, and the design scheme is reasonable and reliable, which can provide a reference for the independent research and engineering application of the electric drive axle of new energy heavy vehicles.