On the basis of geological map in surface, well and seismic data, the authors discuss the structural interpretation model, and conclude that the model of "detachment fold pile on the top of basement-involved thrust" could be more reasonable. The anticline in the shallower level detached in the salt-gypsum rock of the Paleocene-Eocene Kumogelie Group or the Jurassic coal-bearing strata and break thrust developed in the anticline, but the deeper under the salt-gypsum rock developed a set of thrusts dipping to North and assembled to a wedge imbricate fan. The tailing fault in the imbricate fan is a basement-involved thrust with middle-high angle, and could be the master thrust as a result of pre-exist regional normal faults inverted. The inverted action of basement-involved normal faults induced the formation of wedged imbricate fan on the foot wall.