Objectives: A set of extremely thick evaporite deposits are widely developed in the Early—Middle Jurassic Quemocuo Formation in the North Qiangtang Basin, Xizang (Tibet) Plateau. In this paper, the lithofacies paleogeographic environment of the Early—Middle Jurassic in the North Qiangtang Basin is restored and the conditions of salt and potassium formation are analyzed.Methods:Based on the data of the Well QK- 1, the Well QZ- 16 and surface outcrop data, this paper uses the methods of stratigraphic division and correlation, sedimentary microfacies analysis, sedimentary sequence research and so on.Results:Influenced by the further expansion of Bangong Lake—Nujiang middle Tethys ocean basin, the North Qiangtang Basin entered the passive continental margin basin evolution stage in Early—Middle Jurassic. Two rift troughs formed by rifting in the depression controlled the deposition of the Quemocuo Formation. The uplift of the central part of Qiangtang makes the sea water only diffuse northward from the narrow channel of Shuanghu Lake. Due to the joint action of seawater and fresh water, a set of coastal lacustrine sediments with saline and brackish water developed in the depression. The sea (lake) level and paleoclimate of the Quemocuo period in the North Qiangtang Basin have experienced many cycles.Conclusion: Under the coupling of semi- closed paleotectonic framework, frequent transgressive salt source supply and extremely hot and arid climate conditions, the Quemocuo paleo- salt lake in the North Qiangtang Basin has the conditions of salt forming and mineralization, and the Bandaohu to Puruogangridi uplift area is the favorable area for salt and potassium.