Aimed to analyze the relationship between landslide distribution and vegetation types, typical landslide areas and tree species was chosen in this research. Pinus tabuleaformis, Pinus armandi, Larix kaempferi, and Quercus aliena are 4 typical tree species widespread in the study area, and their root distributions and mechanical characteristics among species were analyzed. The unmanned aerial vehicle images were used to obtain the landslide density in different vegetation areas according to different physiological characteristics of leaves. Root investigation within 100 cm depth soil by soil profile method was used to quantify root number and diameter distribution, indoor experiments were conducted to test the tensile strength of each single root for root additional cohesion evaluation. Finally, the safety factors of slopes with different vegetation types under different water conditions and slopes were calculated combining with forest survey results and the mechanical properties of rock and soil. The results showed that: (1) The P. tabuleaformis and P. armandi forests have higher landslide density than the L. kaempferi and Q. aliena forests in both high and low landslide density areas. (2) The root number, distribution depth, and tensile strength of single root of Q. alienawas significantly greater than those of P. tabulaeformis, P. armandi, and L. kaempferi. The root vertical distribution of Q. aliena was more than 100 cm, the root maximum tensile strength was (32.551±7.551) MPa, and the root average cohesion was 9.364 kPa in 100 cm depth. (3) When the rock and soil were in saturated extreme precipitation condition, the contributions of P. tabuleaformis, P. armandi, and L. kaempferito slope stability were negative, while Q. alienacould efficiently reinforce the slope and had good function of preventing and controlling the sallow landslide.