Dispersive soil disperses when exposed to water, if a damaged underground water conveyance pipeline in dispersive soil area leaks, the ground collapse and damage is likely to happen. To explore the related influencing factors and their action patterns, a self-developed water conveyance pipeline leakage test device was used to investigate how the size of the pipeline damage aperture, damage location, soil properties, and flow rate affect soil erosion damage. The test results show that the larger the size of the pipeline damage aperture, the greater the degree and speed of soil collapse and damage. Compared with damage apertures on the side and bottom of the pipeline, the ones located at the top are more likely to cause ground collapse problems. When the pipeline damage aperture is small, there is no significant impact on the soil surface in the early stage of leakage, but as the flow rate increases, the ground collapse and damage will eventually happen. Compared with non-dispersive loess, dispersive soil can cause greater ground collapse and damage under the same conditions. Using non-woven fabric to treat the most severe damage pattern can improve the loss of soil particles and effectively inhibit soil damage.