The northwestern margin of Jungar Basin was located within the large-scale thrust-nappe structures during Triassic period and the margin of the basin experienced intense syn-sedimentary faulting, resulting in the formation of glutenite fan delta. Based on cores observation and decription, thin sections identification and SEM observation, loggin, and physical property data of glutenite reservoir in the Mabei area, lithoglical compositions, layer types and sedimentary sequences of glutenite were discussed in detail to establish the lithofacies model. This study identified 11 glutenite lithofacies: Glutenite facies of underwater channel in the fan delta front and superimposed large-scale braided channel glutenite facies of fan delta plain are most favorable reservoir facies; conglomerate facies at estuary subaqueous distributary channel, sandstone facies at the end of the underwater channel and sandstone facies at estuary-distal sandbar are of limited distribution and regarded as the favorable "sweet spot" area due to their good reservoir potentiality; superaqueous mudslides conglomerate facies, subaqueous mudslides conglomerate facies, and poor accumulation fine-grained sediments deposited at fan-dalta and front stream jointly constituted tight roof and floor of the Baikouquan reservoir. The siltstone facies and mudstone facies of the frontal fan delta can be regarded as a good regional cap rocks. Diffferent lithofacies and sedimentary conditions have provided favorable reservoir-cap assemblages and roof-floor conditions for large-scale low permeability lithological reservoir in the Triassic Baikouquan Formation in the Mabei area.