通过对Ｄ系列柴油机排放水平实测数据的分析，摸清了降低排放的切入点和成因，并对燃油喷射系统、增压系统、燃烧系统及机油耗控制等方面进行了理论研究与优化试验．采用１００ＭＰａ的高压喷射技术，改善了油气的混合过程，完善了燃烧性能；改进活塞和活塞环结构尺寸有效地降低了机油耗；带排气放气阀的增压系统较好地解决了最大扭矩工况时α偏低的问题．最终的技术方案使Ｄ系列柴油机排放的ＮＯｘ下降４７．２％，颗粒ＰＭ下降２０％，全面达到了欧洲Ｉ排放标准 Through the analysis of measured data of D series diesel engine emission levels, we find out the starting point and causes of reducing emissions, and theoretical research and optimization experiments on fuel injection system, supercharging system, combustion system and fuel consumption control. 100MPa high-pressure jet technology is adopted to improve the mixing process of oil and gas and improve the combustion performance. The improvement of the piston and piston ring structure size effectively reduces the fuel consumption; the supercharging system with exhaust bleed valve better solves the problem of maximum torque Low α when working conditions. The final technical solution makes the D series diesel engine emissions of NOx decreased by 47.2%, particulate PM decreased by 20%, fully meet the European I emission standards