The invention relates to an inertial linear piezoelectric motor. Comprises a bottom plate, a slider, a sliding rail, two mass blocks and a piezoelectric stack; The bottom plate is an elongated plate,one end of which is connected with a slider, and the other end of which is connected with a vertical structure part and a horizontal structure part through a flexure hinge. The vertical structure andthe horizontal structure are hollow rhombus structure with the same structure. The piezoelectric stack is arranged in the hollow rhombus structure of the vertical structure part; the piezoelectric stack is arranged in the hollow rhombus structure of the vertical structure part; The slider is fitted on the slide rail to realize linear sliding along the slide rail. When a harmonic signal of a firstorder frequency is inputted to the piezoelectric stack to produce a first order resonant mode, the whole inertial linear piezoelectric motor moves to the right, and when a harmonic signal of a secondorder frequency is inputted to the piezoelectric stack to produce a second order vibration mode, the whole inertial linear piezoelectric motor moves to the left; As that frequency of the harmonic signal apply to the piezoelectric stack is changed, different vibration mode of the motor can be generated and the movement direction of the motor can be changed.