Due to the huge reclamation area of Hengsha Phase 8 project，the soil quality of the reclamation is diverse and the distribution is different. To study the change law of the soil quality of the blown fill in the super-large enclosed area，the distribution law of the horizontal and vertical blown fill at the mouth of the blown fill pipe is analyzed through borehole sampling of the actual blown fill site. The results show that the depth of about 3.0 m below the surface of the filling soil in the super-large enclosure area is basically silt，and the depth below is fine sand. Within the range of about 150.0 m from the mouth of the filling pipe，fine sand is the main component，and outside this range，silt is the main component. These results can provide a useful reference for pipeline layout and flatness control in the process of land reclamation.