Abstract: The deformation simulation method of core wall dams has always been a hot and difficult topic in the industry. Traditional grid-based methods, such as the finite element method, the finite volume method and the finite difference method, are often applied to deformation analysis. However, when dealing with large deformation problems, the Jacobian matrix becomes abnormal due to mesh distortion, making the calculation impossible. Therefore, within the basic framework of the material point method, this paper constructs the convective particle Gaussian interpolation function and combines it with the particle interpolation function to propose the adaptive interpolation material point method (AIMPM) applicable to fluid-solid coupling problems. Taking the landslide of the Carsington core wall dam as an example, the AIMPM is used to analyze the evolution law of the whole process from the construction period to the instability and landslide of the dam. The results show that: 1. According to the actual construction situation of the dam, the AIMPM can accurately describe the development process of deformation and pore pressure during the construction stage of the dam body; 2. Under the condition of obtaining the initial stress during the construction of the dam body, the Adaptive Interpolation Material Point Method (AIMPM) can simulate the complete evolutionary process of the dam from the formation of the initial sliding surface to the final accumulation body after the dam break; 3. By capturing the running characteristics of particles, the failure process of the dam body can be divided into three stages: the rigid body displacement stage, the stress equilibrium stage and the velocity convergence stage. Through the refined simulation of the classic core wall dam, it is indicated that the adaptive interpolation material point method proposed in this paper can be flexibly applied in both the small strain and large deformation fields, providing an effective approach for the deformation and failure analysis of core wall dams.