As a critically important transportation infrastructure in China, highways play a significant role in supporting socio-economic development. However, due to the rapid growth of the current socio-economic landscape and the dramatic increase in the number of cars, many early-built highways have experienced a surge in traffic volume, making it difficult to meet the growing traffic demand. This has led to various issues such as traffic congestion and inefficient operation. Therefore, it is necessary to expand and reconstruct the highway interchanges, effectively optimizing traffic organization design and significantly improving the overall service level of the highway. This article provides a detailed analysis of the principles and key points of traffic organization design for the expansion and reconstruction of highway interchanges. Additionally, it delves into the design scheme for the traffic organization of these interchanges.