Abstract: According to the investigation of earthquake damage over the years, the slippage of the column foot is a typical damage of the column base connection part of ancient timber structures in Sichuan areas. In order to predict the slippage of the column foot and determine the degree of earthquake damage of ancient timber structures, the column base connection is chosen as the research object. The connecting part is simplified into horizontal and rotating springs, then the dynamic equations of structures are established accordingly. In the solution process, the irregular seismic excitation is simplified, and the peak excitation is used as the constant input. The equivalent stiffness and the correction coefficient are introduced to modify the equation and the solution results, and finally the expressions of the slip distance of the column foot, the maximum slip distance and the maximum inclination angle of the column are obtained.