Abstract: The morphological characteristics are a fundamental prerequisite for the development, evolution, mitigation, and prevention of landslide dam hazards, necessitating urgent theoretical quantification. A comprehensive experimental setup is designed to simulate the entire process of landslide-induced river blockage and dam formation. Structure from Motion (SfM), a three-dimensional reverse reconstruction technology is employed to quantitatively analyze the morphological characteristics. Based on typical cross-sectional and longitudinal profiles, a computational method for landslide dam volume is derived. Experimental results and theoretical analysis reveal that fine particles are predominantly concentrated near the sliding-side, while coarse particles gradually increase toward the far sliding side and the valley's free surfaces along the sliding direction. At smaller sliding angles, the source material tends to accumulate on the near-slide side, with the lowest point situated on the far side. When the sliding distance is short, the highest point of the landslide dam is located on the near-slide side of valley; as the sliding distance increases, the peak elevation shifts toward the far side of the river channel. A volume calculation method is derived using cut-and-fill technique and length as a correlating parameter. Subsequently, a quantitative model for morphological characteristics is established by incorporating the static angle of repose, sliding angle and sliding distance. The computational model yields errors of less than 15% for volume calculations, height, base width, and length. The study results confirm that the proposed quantitative model effectively captures the influence of varying static angles of repose, sliding angles, and sliding distances on the morphology of landslide dams. This advancement provides a robust basis for assessing and predicting the scale of landslide dam hazards.