Abstract: Incomplete combustion has posed the a great challenge on to the performance of engines in the high-altitude areas, due to the thin air and reduced oxygen content. The in-cylinder “oil-gas-chamber” matching can be expected to restore the engine performance at altitude. The oOxygenated fuels can also be considered to be the most effective alternatives. This study aims to improve the oil-gas-compartment matching using oxygenated fuel-biodiesel. Two types of combustion chambers (the prototype ω and the optimized TCD (T-turbocharger, C-intake air cooling, and D-diesel particle filter) were simulated and experimentally validated using AVL FIRE software. The performance of the TCD combustion chamber was then evaluated under different fuel types (B0 (pure diesel), B10, B20, and B50) and various speeds. A systematic investigation was finally implemented to explore the effects of biodiesel blending in the combustion chambers on the agricultural diesel engines. The results show that the TCD combustion chamber was enhanced the oil-gas mixing and air utilization in the cylinder, due to its unique convex structure. Thus, the more complete combustion of the fuel was has improved the performance of the engine system. Biodiesel was also promoted promotes the combustion efficiency with the less harmful emission, due to its oxygen content. Furthermore, the TCD combustion chamber also shared the higher indicated power, thermal efficiency, indicated in-cylinder peak pressure, and temperature, compared with the prototype ω ones. While there was the a decrease in the fuel consumption rate. Specifically, the TCD combustion chamber showed the largest increase in the indicated power at a speed of 3000/(r·min-1). The indicated power values were 14.10%, 13.76%, 13.43% and 12.44%, respectively, when burning B0, B10, B20 and B50, respectively. At the same time, the maximum decrease in the indicated fuel consumption rate was 12.36%, 12.09%, 11.85%, and 11.07% respectively. The higher NOx emissions were observed in the TCD combustion chamber, compared with the prototype ω ones. There was the an increase in the NOx emissions with the increasing speed and proportion of biodiesel in the fuel blend. The reason was that the higher in-cylinder temperature of the TCD combustion chamber was greatly promoted to produce the NOx emissions. The self-contained oxygen of biodiesel was also participated during the reaction. A higher higher-quality of in-cylinder oil-gas mixture was also found in the TCD combustion chamber. The more NOx emissions were also attributed to the more oil-gas mixture with the higher quality and wider diffusion area. Correspondingly, the soot emission of the TCD combustion chamber was significantly lower than that of the prototype ω ones. There was the a decrease in the soot emission with the increasing speed and biodiesel percentage. Therefore, the diesel engine systems can also be expected for the oxygenated fuels in the high-altitude environments. The performance of the engine can be optimized to improve the working efficiency and environmental friendliness in the high-altitude areas. Biodiesel can be effectively reduced the environmental impact of diesel engines, in order to improve the combustion efficiency with the less emissions. The findings can also provide a strong reference for the future engine design and fuel strategies. Diesel engines can be remainedremain on an efficient and environmentally friendly solution in the high-altitude areas.