The invention discloses a three-dimensional seismic data fault enhancement processing method. The method comprises steps: based on a seismic data volume, a time window range of a target stratum is determined, and the seismic data volume is preprocessed; the attributes of the seismic data volume are counted to calculate a structural guidance body; based on the structural guidance body and the seismic data volume, a seismic coherence cube in the time window range of the target stratum is calculated; based on the seismic coherence cube and the attributes of the seismic data volume, the coherencevalue of each piece of seismic data in the seismic data volume is acquired, and a threshold value is set; and in view of seismic data with the coherence value smaller than the threshold value, diffusion filter processing is adopted and a diffusion filter data volume is acquired, and in view of seismic data with the coherence value greater than the threshold value, median filter processing is adopted and a median filter data volume is acquired, and the diffusion filter data volume and the median filter data volume are integrated to acquire a fault enhancement data volume. Through combining thediffusion filter processing and the median filter processing, the fault recognition precision is improved, and the problem of continuous section information and horizon enhancement can be solved.