Abstract: Calculating the seismic active pressure on sheets between anti-slide piles or stabilizing piles remains a longstanding challenge for engineers and technicians. According to the characteristics of soil sliding surface between piles based on the generalization of a series of experiments, a three-dimensional sliding wedge model for the instability of local soil is established. By calculating the internal energy dissipation rate and the external load power of the three-dimensional instability mechanism, an analytical procedure for seismic active pressure calculation is proposed based on the limit analysis theorem. By comparing the seismic active pressure acting on sheets between piles with that on rigid retaining wall, it is found that the earth pressure on sheets by using the three-dimensional sliding wedge model is less than that on retaining wall by using the plane strain model. The analysis of multiple combinations of horizontal and vertical earthquake accelerations, indicates that both the horizontal seismic acceleration and the vertical earthquake acceleration have significant effect on the active earth pressure of sheets between anti-slide piles, and that the active earth pressure considering bi-directional seismic action is greater than that considering horizontal earthquake effect or vertical earthquake effect separately.