Natural-draught furnaces are widely used in various industrial applications, but achieving optimal combustion efficiency remains a challenge due to inherent design constraints and variability in fuel properties. This study explores the application of Computational Fluid Dynamics (CFD) to enhance combustion processes in natural-draught furnaces. By employing CFD simulations, we analyze the flow dynamics, temperature distribution, and combustion characteristics within the furnace. The study focuses on adjusting key parameters, such as airflow rates and burner configurations, to optimize combustion efficiency and reduce emissions. The results demonstrate significant improvements in combustion performance, including better fuel utilization and lower pollutant levels. This approach offers valuable insights for optimizing natural-draught furnace operations, contributing to more efficient and environmentally friendly industrial processes.