Abstract: An improved backstripping inversion method of original stratum thickness was applied to Wuyang salt basin.The method considered erosion,salt movement,interlayerd bedding,and abnormal compaction in the basin.By using this method we can calculate the original stratum thickness and lithologic proportion in every sedimentary telophase based on nowadays stratum thickness,lithologic proportion,abnormal compaction,and salt thickness,which is very important to embedding history analysis and tectonic evolvement analysis in salt basin.