The embodiment of the invention provides an earthquake reflection coefficient determination method and device; the method comprises the following steps: obtaining earthquake signals of a target zone,wherein the earthquake signals comprises amplitudes of a plurality of sampling points in the target zone; determining attraction fixed points in the earthquake signals; determining sampling points corresponding to the attraction fixed points as reflection point positions; determining an earthquake reflection coefficient according to the reflection point positions and earthquake signals. The methodfirstly determines attraction fixed points in the earthquake signals, and determines earthquake reflection point positions via the attraction fixed points, thus further determining the earthquake reflection coefficient, and solving the technical problems that an existing earthquake reflection coefficient determining method is poor in accuracy; the method and device can fast and accurately determine the earthquake reflection coefficient.