Although traditional Chinese wooden residential buildings have historically adapted to their respective regions, they face challenges in meeting modern living standards, particularly with regard to insufficient indoor natural lighting. This study focuses on three representative Tujia residences: the “L-shaped” dwellings, the “U-shaped” dwellings, and the courtyard residences, with the aim of improving their indoor lighting performance. Using Ecotect 2011 software for computer simulations, the study investigates the impact of altering the geometric shapes of courtyards in traditional wooden residential buildings on the lighting of the central room. The results indicate that, for the “L-shaped” dwellings, the geometric dimensions of the courtyard have little impact on the lighting of the central room. For the “U-shaped” dwellings, the optimal courtyard geometry is achieved with a well index (WI) of 1, balancing residential functionality, economic considerations, and indoor lighting performance. Regarding the courtyard residences, the best results are obtained by minimizing the building height while maximizing the well depth index to 1. Additionally, the study shows that a square layout of 90° ∗ 90° is most favorable for courtyards, effectively balancing lighting performance, functionality, and aesthetics. These findings provide valuable insights for the renovation of existing traditional residences and the design of new buildings, aiming to enhance overall indoor lighting effectiveness.