Abstract: Long-distance transport pipelines are prone to produce large deformation under the influence of severe geological hazards, such as active fault belts and goaf subsidence areas, which may lead to critical safety incidents, such as oil and gas leaks or explosions. To address the challenge of the large deformation monitoring and shape reconstruction of pipeline structures, a novel inverse absolute nodal coordinate formulation (iANCF) is proposed upon the inverse finite element method (iFEM) and upon the absolute nodal coordinate formulation (ANCF). Focusing on the large deformation of a planar cantilever beam, the iANCF plane beam element is constructed. A weighted least-squares functional is established using the absolute coordinates and angles of the nodes to be determined, along with the bending curvature and axial strain derived from the known surface strain. By introducing the curvature continuity boundary condition and, by simplifying the node degrees of freedom, the well-posed nature of problem is ensured, and the accurate solution can be obtained through Newton method. Finally, the numerical simulations and test results show that the method can reconstruct the deformation with high precision of a cantilever beam under different loads, and thusly monitor the complete deformation process of a pipeline with the action of active fault belts. It has great potential power in solving the large deformation monitoring problem of pipeline structures in severe geological hazard areas.