As China's industrialization process accelerates, especially in the printing and packaging, petrochemical and coal chemical industries, the volume of exhaust air treatment continues to rise, so the idea of a modular Double Rotary Regenerative Thermal Oxidizer (D-R RTO), which can effectively reduce the cost of design, has emerged. This paper takes the pre-studied D-R RTO as the research object, establishes the three-dimensional model and fluid domain model of the D-R RTO by using Solidworks software, and performs numerical simulation by using the Computational Fluid Dynamics (CFD) software Fluent. Based on the Box-Behnken design (BBD) response surface methodology, response surface analysis experiments were designed and implemented to reveal the interaction between the operating parameters such as inlet air volume, exhaust gas concentration, and commutation period on the D-R RTO thermal efficiency and purification rate. The experimental results can guide the precise regulation and control of the actual production of three-bed regenerative oxidizer.