The invention provides a sand shale rock reservoir stratum pressure earthquake prediction method and device; the method comprises the following steps: calculating the elastic modulus, the microfissure density and microfissure closed rate factors under the limited effective stress according to a Hashin-Shtrikman boundary model and the porosity and shale content of an object sand shale rock reservoir in a research zone; determining the relation between the dry rock elastic modulus and effective stress according to the elastic modulus, the microfissure density and microfissure closed rate factors; determining the effective stress coefficient of the sand shale rock along with the depth changes according to said relation; predicting the stratum pressure of a single well to-be-detected object layer according to said relation and the effective stress coefficient; using an elastic modulus data body obtained by inversion and taking the single well stratum pressure as constraints, and carrying out three dimensional earthquake stratum pressure prediction on the research zone according to said relation and the effective stress coefficient. The method and device can improve the stratum pressure prediction accuracy.