Abstract: Digital twin is widely regarded as a key technology to realize the cyber-physical interaction, and the augmented reality technology, as an effective means to assist the virtual-real interaction of digital twin, provides a solution for the interaction of human, pipeline digital twin and on-site environment. Therefore, a digital twin framework for structural safety assessment of underground pipeline networks was proposed by integrating the technologies of digital twin, augmented reality and distributed optical fiber monitoring. Meanwhile, the theories of building the physical pipeline networks, virtual pipeline networks and digital twin service based on augmented reality were elaborated. On this basis, the method was applied to an underground pipeline network. The results show that the safety assessment method of underground pipeline networks under the drive of the integrated digital twin and augmented reality realizes the one-to-one mapping between the virtual pipeline networks and the physical pipeline networks in the on-site environment. Furthermore, the real-time quantitative assessment on conditions of pipeline structure based on digital twin helps the field operators to more comprehensively perceive, understand and surpass the real world, providing technical support to improve the efficiency of on-site disposal.