The Junggar Basin is a typical superimposed basin in western China. However, the prototype basin of the Early Hercynian period has long been controversial, which has seriously restricted the understanding of the petroleum geological conditions in the ultra- deep layers of the basin and the progress of exploration.Methods:Based on the basin's largest dataset of high- precision contiguous 3D seismic data, well logging data, mud logging data, geochemical analysis data, and dating data, the authors have conducted studies on regional stratigraphic correlation, tectonic evolution analysis, hydrocarbon- controlling factors, reservoir- controlling factors, and hydrocarbon accumulation processes.Results: The results show that: ① Vertically, the Carboniferous System in the Zhongguai Uplift of western Junggar Basin develops a fourfold structure of “volcanic rocks + clastic rocks + volcanic rocks + clastic rocks” similar to that in the eastern part of the basin, with a regional unconformity existing between Member b and Member a of the Songkarsu Formation. ② The Zhongguai Uplift has experienced four major evolutionary stages: “intracontinental extensional rifting during the Early Hercynian, intense compressive uplift during the Middle—Late Hercynian, slow uplift during the Indosinian, and southward tilting adjustment during the Yanshanian—Himalayan Periods”. An aulacogen developed in the Carboniferous Period, extending in a northwest—southeast direction from the Zhongguai Uplift southeastward to the Mosuowan Uplift—Monan Uplift. ③ Source rocks are developed in the two flanks of the Zhongguai Uplift, while large- scale volcanic rocks are developed in the aulacogen area at the core. Intense erosion caused by compressive uplift during the Late Hercynian formed large- scale high- quality reservoirs, resulting in two types of oil and gas reservoirs within the aulacogen: the “self- generated and self- reservoired” inner- type reservoir and the “dual- source hydrocarbon supply” weathering crust- type reservoir.Conclusions: The research results provide important petroleum geological implications for the oil and gas exploration of the aulacogen in the Zhongguai Uplift.