Abstract: Abstract: The time-depth conversion faces many difficulties in some special conditions, such as rugged seabed, deep-water and the areas of low exploration degree, owing to the deficiency in seismic, sha-llow drilling and improper velocity data. The fitting formula by removing water depth was the only method for time-depth conversion. However, the practice may lead to pseudo-structures because of rugged seabed，and the conventional correction method by filling up the sea bottom has similar shortcomings. The method used in this paper calculate the time-to-depth horizon first, and then compare the horizons in depth-domain for the change in the transverse structures. This method introduced in the concept of structure similarity rate and quantitative templates are built up for filling up the sea bottom for correction of the rugged seabed. Based on the highest score value, the suitable sea bottom and time-to-depth horizons are determined. To some extent, it can eliminate the pseudo-structures caused by rugged seabed and better support the requirements of structural mapping.