Alluvial fan is a typical continental fan accumulation formed after the outflow of the river (flood). There are two kinds of sedimentary mechanism, the traction flow and the debris flow in the fan root area，which make the sedimentary model of alluvial fan complicated. The exposed alluvial fan phenomenon is well in Zhebu countryside, Laiyang city, Shandong province, which belongs to Cretaceous Wangshi group Xingezhuang Formation. Through the detailed observation and measurement on the section, using the sedimentary principle of the outcrop, the sedimentary environment was thought being an alluvial fan, which developed chaotic accumulation of conglomerate facies (Gms), massive bedding conglomerate facies (Gmh), trough cross bedding sandstone facies (St), planer cross bedding sandstone facies (Sp), horizontal bedding sandstones (Sh), floodplain mudstone (Fl) and massive bedding mudstone (M). The trough flow facies belt, slice flow facies belt, braid flow facies belt, runoff facies belt were identified. The facies of the trough flow belt and the slice flow facies belt were the least exposed, and the upper part of the main section was mostly debris flow deposits. The facies of the runoff facies and the braided flow facies were the most exposed, showing the characteristics of the interaction between sand and mud. In view of this, based on the study of the sedimentary characteristics of different facies zones, the sedimentary model was established and the evolution characteristics of the profile were analyzed combined with the outcrop characteristics of alluvial fan in Laiyang, Shandong province.