Abstract: To solve the imaging bottlenecks in the seismic exploration of complicated structural zones in Bohai Sea region, such as for the secondary fault development zone, high steep structural zone, regional velocity abnormality zone and buried hill inner curtain zone, this article comes up with a technical method which is based on high-resolution velocity model building and uses Gaussian beam depth migration for improvement of complicated structural imaging quality. High-resolution velocity model building is for the purpose to work with TTI velocity model and use high-resolution tomographic inversion technology to obtain more accurate model. Gaussian beam depth migration method is the high-frequency asymptotic time harmonic solution of elastodynamic equation concentrated near rays. It overcomes the shortcomings of standard ray method that the amplitude changes sharply and non-fixedly near the caustic surface. It can also ensure normal response from complicated structures. Actual data processing indicates that joint application of the two technologies improves imaging quality of high steep structures and complicated faults in Bohai Sea region, thus improving the quality of seismic data.