The invention provides a crack prediction method based on maximal energy ratio method. Through the method, the "angle - time difference" spectrum of the fast and slow shear wave splitting can be calculated to obtain the crack orientation and density parameters conveniently. The method comprises the following steps of conducting horizontal component rotation for vertical seismic profile data to obtain a rotated component and separating to obtain descending wave field of the rotated component, selecting an appropriate time window for the detection point of each target depth, so that each time window comprises a downlink R and a set of conversion wave field generating shear wave splitting on T component, scanning and calculating angle - time difference spectrum for data in the time window by using improved maximal energy ratio method, and finally extracting the relative azimuth of the crack and fast and slow wave time difference from the angle-time difference spectrum and calculating the natural azimuth and density of the crack.