Abstract: Oil and gas pipeline network reconstruction is one of the difficulties in engineering project evaluation. This paper proposes the input/output analysis model for such construction by dividing the benefits thereof into security benefits and economic benefits and establishing the long-term pipeline failure tree which takes the "pipeline failure" as top event. Firstly, the security benefit is quantified by multi-level fuzzy comprehensive evaluation through solving the probability importance and critical importance of basic event and minimal cut sets. Secondly, the economic benefits are divided into output by loss reduction (which considers reduction of personnel losses, social loss, ecological and environmental damage, equipment loss, maintenance & inspection and others) and output by value addition (which considers the increased throughput due to longer life of the pipe network). Then, with the risk-based evaluation methods, and according to the international, national and industry standards, the economic benefits are calculated. Finally, with the data of specific reconstruction project, the model is used to objectively evaluate the input/output of crude oil pipeline network reconstruction.