As an important part of the New Austrian Tunneling Method construction (NATM), the processes of monitoring and measurement are important and indispensable in the tunnel construction, which effectively reflect the rock deformation and its mechanical behavior, and provide a suitable installation time for tunnel lining structure. Scientific analysis and forecast real-timely on monitoring data provide a precondition for supporting the strategic decisions of construction organization, as well as dynamic design. In this paper, the tunnel monitoring method and datum analysis are illustrated through an example of the port tunnel monitoring in Jing wuhuang (chang) highway, Jiangxi province china. Many items monitoring data (vault sinking, peripheral convergence, surface settlement, bolt axial force and drawing force, internal force of steel timbering, internal force of secondary lining) acquired from the field monitoring have been analyzed. The appropriate opportunity of surround rock stabilization after tunnel excavated and second lining are proposed by the analyzed the monitoring datum which can provide some lesson for the future tunnel construction.