The invention discloses an impact damage rock sample preparation and assay method based on an SHPB test and belongs to damage rock sample preparation and assay methods. The method comprises the steps that firstly, a cylindrical rock sample is manufactured, an SHPB device is used for conducting impact pre-damage on the cylindrical rock sample at an air pressure value lowered than the critical air pressure, corresponding stress waves are recorded, and the dynamic strain peak value, the strain rate peak value and the unit volume absorbing energy are acquired through calculation; secondly, the circle center of the end face of the rock sample serves as a center point, and axial drilling is conducted to form a cylindrical standard damage sample; thirdly, macro and microscomic testing of CT scanning, nuclear magnetic resonance, a longitudinal wave speed, a permeability coefficient, elasticity modulus, uniaxial compression strength and the like is conducted on the standard damage rock sample; fourthly, the same macro and microscomic testing is conducted on standard complete rock samples with the same rock character and physical parameters; fifthly, the dynamic damage degree of the impact to the rock material is quantitatively judged with the dynamic strain peak value, the strain rate peak value, the unit volume absorbing energy and other impact effect parameters as the bases by combining the data of the macro and microscomic testing. The method has the advantages that operation is easy, and the test data are comprehensive and reliable.