Abstract: With the growth of energy demand, large gas turbines are playing an increasingly important role in power generation, aviation, etc., and have become one of the important technical approaches for improving energy efficiency and reducing emissions. The combustion chamber transition section, as a key component, has a significant impact on the overall performance. This article introduces the aerodynamic design and function research of the combustion chamber transition section of large-capacity gas turbines; analyzes the role, difficulties, and position of the combustion chamber transition section in gas turbines; uses CFD technology combined with various optimization methods to optimize the design of the combustion chamber transition section; proposes a new aerodynamic model applicable to the transition section, and can calculate accurate parameters such as flow rate, pressure loss, and temperature rise, to guide the design work, and minimize aerodynamic losses while ensuring smooth airflow.