Abstract: Submarine landslides are a common marine geological disaster characterized by large volume, fast speed, significant disaster-causing effect, and huge range of impact, which can damage marine engineering structures, resulting in significant economic losses and casualties, and seriously threatening ocean engineering construction and resource development. These are especially dangerous to submarine pipelines and cables, which are both essential for offshore energy transport and international communication. To study the dynamic process of a submarine landslide impacting a submarine pipeline, a physical model testing device was developed, consisting of a transparent cubic tank, an automatic valve to release landslides, adjustable slopes, and a simulated pipe with four pressure sensors to measure the impact force and lifting force during the whole impact process. The device accurately simulates the interaction between the submarine landslide and pipeline, investigating the force characteristics of the pipeline under the impact of the landslide to obtain informative test data. Based on the images and data from the test, the mechanism of submarine landslides sliding and impacting pipelines could be summarized into four stages: erosion initiation, impacting pipeline, passing pipeline, and landslide accretion. In contrast to previous studies that only focused on the impact force on pipelines along the slide, both the impact force and vertical lifting force—which may also lead to pipeline destabilization when pipelines are struck by landslides—are the focus of the model test, contributing to a more comprehensive understanding of the interaction mechanisms between submarine landslides and pipelines. The test data uncovered the influence of submarine landslide volume, landslide slope, submarine pipeline diameter, and span height on the impact force, which is systematically analyzed by illustrating the time history and peak force of these different factors. It was found that both the peak impact force and lifting force occurred at the beginning of the impact on the pipeline when the landslide front reached the pipeline. The impact force then decreased sharply to near zero, while the lift force also decreased but ultimately remained oscillating around a small residual value. The impact force of the submarine landslide on the pipeline is directly proportional to the slope volume, the square of the landslide velocity, and the diameter of pipeline. The peak impact force on the pipeline is negatively correlated with the span height of the pipeline. Furthermore, the peak value of the vertical lifting force is approximately 1/5 of the peak impact force. Compared with the empirical formula, the phenomenon and analyzed results of the modeling test shows that finer soil particles are more likely to be eroded by water and are prone to turbidity currents. This suggests that the particle gradation of submarine landslides affects the motion state and impact characteristics of submarine landslides to some extent, which is not considered in this test and requires further study. The results of this study not only deepens the understanding of the interaction between submarine landslides and pipelines, but also provides a scientific basis for future submarine pipeline design and safety assessment of submarine pipeline systems.