Abstract: In order to study the bearing characteristics of the compound curved middle-wall of the multi-arch tun? nel during dynamic tunnel excavation, based on the Hejiadaling tunnel on the Yuelushan-Ningxiang highway, the axial force of main reinforcement and strain of concrete at the shoulder of middle-wall are monitored by embedded components. According to the data from the site monitoring, the development process of axial force of main reinforcement is divided into several stages, the law of axial force development of main reinforcement is analyzed, 3 typical bearing modes of middle-wall and the development process are summarized, and the instability types of middlewall under different bearing modes are concluded. The relationship between principal strain of concrete at shoulder of middle-wall and time is interpreted by the bearing modes of middle-wall and the development process, and the rationality is verified thereof.