The invention relates to a method for analyzing radiation properties of high-resolution SAR (synthetic aperture radar) satellites, and belongs to the technical field of overall designs of SAR satellites. The method has the advantages that radiation property indexes of various satellite-borne SAR working modes are accurately computed, and system design results are inspected and rechecked for the high-resolution SAR satellites and the high-resolution SAR satellites in variable-repetition-frequency modes in particular; echo signal energy starts to be computed point by point along imaging time from single-pulse radar equations, accordingly, time-dependent variation conditions of antenna gain, ground-object back-scattering coefficients, slope distances and radar scattering areas of the SAR satellites can be sufficiently reflected, accurate imaging echo signal energy can be obtained, and the accurate radiation property indexes of the high-resolution SAR satellites further can be obtained.