The tight tuff gas reservoir in Huoshiling Formation of Dehui Rift is now an important part of the available hydrocarbon resources in the south of Songliao Basin. The stratified tuff is typical of gas reservoir in the WellDsh101 tract of Dehui Rift, heterogeneity in its physical property strong, tuff reservoir of different fault terraces discontinuous in the region, and fault blocks are of the characteristics which are differential charging in different fault blocks and variable gas-bearing in the same fault block. To complete finely characterizing tuff gas pool, Prestack Depth Migration Processing Technology based on Integrated Velocity Modeling Optimization by which deep seismic imaging quality has been improved, and accurate imaging on the small faults and geo-bodies under complex tectonic movement background completed to provide data base for the identification of interlayer micro-fracture and the characterization of premium reservoir at interval level, and the tuff reservoir prediction and finely effective trap characterization technique based on complex structural background by which a technical flowsheet of fine characterization of effective traps in complex fault-block tuff gas reservoirs has been established for Dehui Tuff and combined with structure and favorable docking zone analysis, effective tuff traps quantitative characterization in main gas-bearing units has been achieved by launching reservoir macro-analysis, prospective facies tract prediction and favorable reservoir characterization, are adopted in this article. Applying the foregoing two key technologies has played a key role in the play optimum seeking and well location deployment on natural gas exploration and development of Dehui Rift. Multi-horizontal-wells deployed in this area have achieved good drilling effects, so that the scale of beneficial reserves is expanded.