A model for analyzing the interaction characteristics between long piles and soil in layered soil is established based on test pile data to address the bearing problem of long piles in layered soil. Based on the analysis model, the influence of sand to clay ratio on the vertical load displacement curve of long piles is studied. The lateral and end resistance bearing ratios of long piles in layered soil are analyzed, and the excitation laws of lateral and end resistance of pile foundations in layered soil are revealed when the ultimate bearing capacity is reached. It is shown that the lateral resistance of the clay layer can be fully excited, the lateral resistance of the sand layer is not fully excited, and the resistance at the bottom of the pile is fully excited. The results provide a basis for selecting reasonable parameters for calculating the bearing capacity of long piles in practical engineering.