There are two large irregular sand sills in the southern Beilaishi profile of Lingshan Island, Qingdao City. The main features are as follows: the upper large irregular sills are distributed in scattered clumps along the yellow- brown tuff mudstone, brokenly with a total length of about 60 meters and a few meters wide;there are 17 intrusive sand clumps (sills).The main sand sills clusters are light grey sandstone and/or conglomerate. Sand clusters are 1~2 m in diameter. The shapes of sand sill cluster are very complex, and the sill side is easily bifurcated, pinched out or abruptly terminated. The boundary and surrounding rock have many abrupt changes, and some places are controlled by joints. The large irregular sand sill in the lower layer is dark gray, mainly composed of sandstone at the bottom and sandy conglomerate at the top. The lenticular shape is produced in the gray- black thin layer of sand and mudstone. The largest thickness is about 18 m thick, and its width and height have not known. Upper sand dikes developed in shallow lakes; The lower large irregular large sand dikes developed in the delta front. The development of large irregular sand dikes in Lingshan Island may be related to earthquake- induced liquefaction. At the same time, the dynamic mechanism of the formation of the upper sand dyke was also discussed, and the relationship between the formation depth of the bedding sand vein and the depth of the liquefaction layer was established (hi= 0.29 Hi).The formula can be used to predict the intruding depth of sills and search for sills, which provides a theoretical basis and a new method for sill- type reservoir prediction in oil- bearing basins. The fluid jet velocity of the upper sill was calculated by minimum fluidization velocity (Umf) formula to be 1.26 m/s. This paper provides new petrographic evidence for understanding the sedimentary environment and sedimentary dynamics of the lower cretaceous in Lingshan island area.