In order to consider soil plugging effect of pipe pile, pipe pile is divided into soil plug part and not considering soil plug part, the horizontal vibration model for part soil plug part exposed pipe pile is established considering the effect of the exposed part of the pipe pile. In the case of ignoring the longitudinal displacement of pipe pile, saturated soil around the pile is regarded as composed by infinite thin soil layers with a round hole, and the pile inner saturated soil is regarded as composed by infinite circular thin soil layers, and the horizontal dynamic forces of saturated soil around pile and pile inner saturated soil on pipe pile are obtained by using mathematical and physics methods. Based on the initial parameter method and matrix transfer method, the horizontal vibration of part soil plug part exposed pipe pile is solved, and the horizontal dynamic impedance of pipe pile is also obtained. The numerical analysis shows that the wall thickness, length of each segment, length to diameter ratio, modulus ratio between pipe pile and saturated soil around pile have great effect on the lateral vibration of part soil plug part exposed pipe pile in saturated soil, and the influence of wall thickness of pipe pile is related with frequency; the soil plugging effect should not be neglected for studying the lateral dynamic impedance of pipe pile.