The Jiulongshan structure in NW Sichuan is located in the 4th Member of the Dengying Formation in the Deyang- Anyue inner craton rift. Investigating the scale and conditions of hydrocarbon accumulation of the Jiulongshan structure has significant theoretical and practical importance for evaluating the potential of deep and ultra- deep oil and gas exploration in this region. Seismic, drilling, and outcrop data were used to analyze basic petroleum geological conditions such as source rocks and reservoirs. Focusing on the structural control of hydrocarbon accumulation, the study clarifies the formation of reservoir elements and the relationship between source and reservoir configuration within the context of structural evolution, ultimately establishing a reservoir formation model. The research results indicate that the structural control of the Sinian Dengying Formation in Jiulongshan can be divided into three important stages. First, during the syn- depositional period, the Jiulongshan structure was located within the carbonate platform of the 2nd Member of the Dengying Formation in the Deyang- Anyue rift. By the time of the 4th Member of the Dengying Formation, it had shifted to the platform margin development zone. The 4th Member exhibits well- developed platform margin sandbars, while the 2nd Member features inner platform sandbars, both representing favorable sedimentary facies zones. Secondly, during the peak development period of the Deyang- Anyue rift in the Early Cambrian, thick and high- quality mud shale layers formed in the Maidiping- Qiongzhusi formations. These, along with the underlying mud shale of the Sinian Doushantuo Formation, serve as the main source rocks for hydrocarbon supply in the Dengying Formation. The interbedding of these two sets of hydrocarbon source rocks with the large- scale reservoir of the Dengying Formation creates a high- quality reservoir formation combination. Third, the Jiulongshan structure underwent continuous local uplift and strengthening, originating from the slope of the ancient uplift in central Sichuan. Through multi- stage tectonic activities and transformation, it ultimately evolved into a local uplift structure in the western Sichuan depression. During the two key periods of oil generation (Ordovician to Early Triassic) and the main gas generation stage (Late Triassic to Early Cretaceous), the anticline structure has formed and continuously strengthened, facilitating the capture and accumulation of hydrocarbons for reservoir formation. Overall, the source- reservoir configuration conditions of the Sinian Dengying Formation in the Jiulongshan structure are superior, possessing the necessary prerequisites for large- scale hydrocarbon accumulation.