Abstract: Seismic data body can be transformed into tuning body by spectral imaging technology.The thickness of strata changes can be identified by amplitude spectrum.PL1~3 wells had been drilled in the area of Penglai A area revealed that the single-layer reservoir thickness of the main purpose layer is big,and the conventional attributes indicate that the reservoir widespread,but the seismic section shows that thickness of the reservoir is significantly changed.In order to study the spatial variation of thickness of the reservoir,this paper carried out a lot of test parameters testing about Landmark software,and ultimately through the optimization of parameters of the forecast reservoir thickness of the drilling is precise confirmed,and this method can be used for similar areas to develop the reservoir prediction.