Abstract: In order to enrich the theory on development and utilization of landslide dam and explore the feasibility of its improvement and reinforcement, the residual landslide dam caused by Yigong landslide was sampled, the indoor vibroflotation model tests with different frequencies were designed, and the reinforcement effect and compaction mechanism of vibroflotation method on landslide dam material were studied. The sand rain method was used for the sample placement in the model tests to comprehensively test the cumulative dissipation law of pore pressure, the development law of earth pressure, reinforcement effect and repeating vibration effect of the foundation after vibroflotation. The test results indicate that the earth pressure and excess pore pressure in the loose landslide dam material rise rapidly during the penetration of the vibrator. Under the pull-up and segmental vibration retention of the vibrator, the excess pore pressure of the landslide dam material showed a general trend of small rise, dissipation and gradual stability. With the increasing number of vibroflotation (after 2-3 repeated vibrations), the soil pressure of the foundation gradually stabilized, and the peak value of excess pore water pressure gradually decreased and tended to be stable. Therefore, the reinforcement effect of vibroflotation on loose landslide dam material was obvious. After vibroflotation, the cone resistance of landslide dam material was greatly increased. However, after the densification of landslide dam material, the increasing number of repeated vibrations was unable to further improve the reinforcement effect effectively. The vibroflotation reinforcement mechanism of landslide dam material mainly included vibrator squeezing, consolidation drainage, and vibroflotation compaction. The vibroflotation design scheme meeting the requirements of Yigong landslide dam material was: vibroflotation with 125 Hz frequency for 4-5 times or vibroflotation with 150 Hz frequency for 2-3 times. The research results can provide a theoretical basis for vibroflotation reinforcement of landslide dam material foundation.