Abstract: When the ballastless track subgrade is constructed in complex and dangerous mountainous areas, it is difficult to solve the potential slip constraint of landslides and settlement control of subgrade by using the existing conventional anti-slide piles or pile-plate structures. To meet the needs of the ballastless track subgrade passing through large landslides, an innovative anti-slide pile and pile-plate structure is designed, and combined with the construction of the Guiguang high-speed railway, the field monitoring tests of the combination structure in large landslides are carried out. The results show that the maximum lateral displacement of both the anti-slide pile and pile-plate structure is located at the top of piles, meanwhile, the lateral displacement decreases with depth. The difference in lateral constraint of the slip surface will cause sudden changes in the lateral displacement of the pile body. The bending moments of anti-slide piles and foundation piles first increase to the peak point and then decrease with the depth, which can be described as a unimodal curve along the pile depth. The bending moments of piles increase in the rainy season, but decrease in the dry season. The anti-slide pile of the combination structure system can be used to control the stability of landslides, and the pile-plate structure is mostly used to control the settlement of the ballastless track subgrade. Therefore, the combination structure can be used as a reinforcement type of ballastless track subgrade in landslides.