In order to reduce uncertainty in the spatial and temporal distribution of source-convergence sedimentary system with low well density, the applicability of the sedimentary forward modeling in the Junggar Basin was discussed. Based on drilling and seismic data of the research area，combined with previous knowledge on the sedimentary background，the sedimentary system of Triassic Jiucaiyuanzi Formation in Well Fu19 area of the Fudong slope，Junngar Basin was simulated forwardly by means of sedimentary forward modelling using the DionisosFlow software. Results show that the far source at Kelameili Mountain located in the northeast to the Well Fu19 area and the point source at the Beisantai uplift are the main sediments supply，the east source in the south of the uplift is the secondary source. As a result，the far-source fine-grained braided river delta front was formed and the near-source hybrid sediments with coarse grains were deposited from the point source. The overall sedimentary evolution was influenced by the frequent lake level rise and fall. Consequently，there are two mid-stage positive cycles in vertical，having the typical lithology characteristics of“sand enveloped by mud”. Good sand body deposited at the front fan delta in the second member of Jiucaiyuan Formation in the periphery of Well Fu19 area，where the effect of lake water dynamic action is weak，together with the superposed mudstone in the shore-shallow lacustrine facies，a good combination of reservoirs and cap rocks can be formed，which is a favorable area for exploration.