为了理清上二叠统梧桐沟组沉积环境，以准噶尔盆地南缘大龙口剖面为例，通过分析岩性、岩相类型，岩相组合、解剖剖面砂体的空间展面规律。总结梧桐沟组3类8种能够表征成因砂体的砾、砂、泥岩相；基于岩相，进一步建立4种岩相组合类型，分别为河道内部、越岸决口扇、河漫滩砂体；通过对剖面岩相组合的分析，在梧桐沟组时期，发育点坝、决口扇、河漫滩沉积亚相，建立随着湖平面变化的曲流河沉积响应模式，并应用露头的研究结果明确了地下储层沉积相与砂体展布。

In order to clarify the depositional environment of the Upper Permian Wutonggou Formation, the Dalongkou section at the southern margin of the Junggar Basin was taken as an example, and the following understanding was obtained by analyzing the lithology, lithofacies types, lithofacies assemblages, and spatial spreading laws of anatomical section sands. Three types of eight gravel, sand, and mudstone phases capable of characterizing diagenetic sands in the Wutonggou Formation were summarized. Based on the lithofacies, four lithofacies assemblage types were further established, representing the point bar, the cross-bank breakout fan, and the fluvial sands, respectively. Through the analysis of the lithofacies combination of the section, the sedimentary subfacies of point bar, crevasse splay, and floodplain in the period of Wutonggou Formation can be further identified, and the sedimentary response model of meandering river with the change of lake level was established. The sedimentary facies and sand body distribution of underground reservoirs were clarified by the results of outcrop research.