Abstract: Submarine pipelines, as important transporting channels of undersea crude oil and natural gas in marine engineering, are usually in the condition of complex marine geological environment and often damaged by the impact of the submarine landslides. The resistance forces of the laid-on-seafloor submarine pipeline impacted by landslides oriented at different angles are studied by using the CFD method based on the Herschel-Bulkley model. Both the computation expressions for normal and axial drag coefficients are provided through the comparison with the published results of model tests. The substantive correspondence between fluid mechanics and geotechnical approaches is found through re-analysis of the data from CFD simulation. Further, the critical suspended distance is summarized by simulating the interaction forces between submarine landslides and pipelines at different suspended distances, and the relationship between drag force and suspended distance is obtained. The research extends the predecessors’ work by enriching the expressions for calculating the axial and normal drag coefficients for pipelines in different suspended states. The proposed formula for estimating the impact force of the submarine landslides on pipelines maybe be practically helpful for selection of router sites and design of pipelines.