Abstract: Under the assumption of horizontal layered media,seismic ray transmission is along the straight line.The hyperbolic equation can be applied in dynamic correction during the actual processing.But actually,subsurface media is not homogeneous and anisotropy may be existed.In this case,it is impossible to achieve high precision dynamic correction by using hyperbolic equation and impossible to flatten far offset under the circumstance of near offset flattening.According to the real existing problems,we described the velocity analysis method-bispectral velocity analysis in the case of anisotropic,put forward a more precise method for velocity calculation and solved the problem of dynamic correction distortion of far offset.