Abstract: In view of the uncertainties in the risk analysis of parallel oil and gas pipelines in tunnel, a risk evaluation method based on cloud model was developed. Specifically, an indicator system of inter-pipeline influencing factors was established based on the potential hazard factors in the operation of parallel pipelines, including the parallel spacing, medium flow rate, tunnel ventilation, tunnel length, pipe diameter, emergency response time, spacing of upstream and downstream cut-off valves, pipe operating pressure and neighboring pipe wall thickness. The objective and subjective weights of the evaluation indicators were determined using the improved hierarchical analysis and entropy weighting method in combination, and the combined weights were obtained by the difference coefficient reconciliation method. The standard evaluation cloud was obtained according to the division of each grade interval, and then the cloud digital characteristics of the parallel pipelines in tunnel were obtained by combining their weights. Besides, the risk levels of the influencing factors between each parallel oil and gas pipeline in tunnel were calculated by the cloud map and the similarity. The method was applied to evaluate the risk between parallel oil and gas pipelines in three tunnels in China. The results show that the risk in Tunnel 2 is the highest, and the appropriate mitigation measures are provided accordingly.