Based on the comprehensive analysis of outcrops, drilling cores, drilling and logging in the Wuerhe-Huanghuagou area on the northwestern margin of the Junggar Basin, combined with microscopic observation, the main petrological characteristics, stratigraphic structure, sedimentary facies types and distribution characteristics of the Lower Cretaceous Tugulu Group were comprehensively analyzed. Guided by the metallogenic theory of sandstone-type uranium deposits, the types and distribution of favorable ore-forming sand bodies in the Lower Cretaceous Tugulu Group in the study area were discussed from the perspective of sedimentology. The results showed：(1)The rock types of the Lower Cretaceous Tugulu a sub-group in the study area are mainly feldspar lithic sandstone and lithic feldspar sandstone, while the Tugulu b, c and d sub-groups are mainly feldspar sandstone and feldspar lithic sandstone.(2)There are four types of sedimentary facies in the Lower Cretaceous Tugulu Group in the study area, which are alluvial fan, braided river, delta and lake. With the Delun Mt. as the boundary, the Wuerhe-Xiazijie area is dominated by shallow-water delta deposits with far-source weak current, while the Delun Mt.-Huanghuagou area is dominated by high-energy braided river deposits.(3)The favorable prospecting horizon of the Lower Cretaceous is the primary gray-gray green coarse clastic formation of the Tugulu a + b subgroup. The branch channel of delta plain subfacies in Wuerhe-Youshashan area is an important prospecting direction. The underwater distributary channel of delta front and the thick sand body of sheet sand widely developed in the Xiazijie area have good lateral extensibility, and have the structure of " mud-sand-mud ". Under the condition of sufficient supply of water source, uranium source and oxygen source, it has the ability to form a certain scale sandstone-type uranium deposit.