According to the basic principles of outcrop sequence stratigraphy, the strata of Permian Longlinian-Lengwuan Stage in Yingen-Ejin Banner basin and its adjacent areas are divided into two third-order sequences through sequence interface identification and sequence classification. The study area inherited the sedimentary framework of the early Permian Xiangboan-Lengwuan Stage, only the deposition range shrank northwestward. The depocenter of Heiyingshan-Ejin Banner depression was Lucaojing area. The water body of Liuyuan-Badanjilin depression became shallow, and the depocenter was Gudongjing area.