A micro-vibration sensor and a preparation method therefor, the method comprising the following steps: coating a metal sheet (10) with a first solidifying material, and solidifying the first solidifying material into a first solidified layer (20) (S100); attaching a piezoelectric thin film element (30) to the edge of the first solidified layer (20) (S200); vertically placing a side of the first solidified layer (20) which has the piezoelectric thin film element (30) attached thereto into a second solidifying material, and solidifying the second solidifying material into a second solidified layer (40) (S300); and removing the metal sheet (10) to obtain the micro-vibration sensor (S400). Since the piezoelectric thin film element (30) is arranged at the tip of a crack (41), the stress in a stress field (42) of the tip of the crack (41) is rapidly increased due to stress deformation of the crack (41) during micro-vibration, and a stress signal is efficiently converted into an electrical signal, thus having the characteristic of high accuracy.