Abstract: Based on the seismic positioning principle we can do 3D prestack forward modeling by one way acoustic wave equation in complex geological conditions.This method has very high caculating efficiency and hasn't multi-reflections in the seismic records.But unsuitable velocity in model usually result in frequency and wave number's lossing of wave-field that cause wave-field's aberration and reduce quality of seismic forward records.This paper proposes wave-field replacement technology which uses new wave-field formed by zero phase wavelet to replace old aberrant wave-field and keep old one's dynamical and spacial characteristic at the same time.It is very suitable to use this technology in 3D prestack forward modeling because the wave-field of focus and receiver's response are similar in shape and every trace's amplitude envelope in wave-field only has one extreme value.The simulation shows that the record's quality is improved when using wave-field replacement technology.