Abstract: This paper examplized the region of Dalujia to discuss the methods and process of complex fault block interpretation.Steps about selecting seismic data,labeling subtle horizon,identificating and combining fracture system,3D seismic stereo interpretation and structure mapping were discussed in details.And the key techniques in 3D seismic tectonic interpretation,such as time-varying wavelet,spectral decomposition coherence and the varying velocity mapping technique,were also emphasized in this paper.It has great results in the practical application.