The plan design for the small-spacing interchange connection on the expressway directly affects operational efficiency and driving safety. To achieve the conversion of traffic flow between different expressways, this study explored the reconstruction plan of the connection section under the condition that the interchange spacing did not meet the Design Specification for Highway Alignment (JTG D20?2017) and investigated two connection schemes, including auxiliary lane and collector-distributor lane by taking the Xinlong–Gangkou interchange of the Zhongshan?Jiangmen Expressway reconstruction and expansion project as an example. The results show that the auxiliary lane is recommended in consideration of the long-term service level, speed coordination, operational efficiency, and engineering scale. The study can provide reference and inspiration for the determination of reconstruction plans for small-spacing interchanges on similar expressways.