Abstract: The reconstruction of sedimentary environments and precise stratigraphic division are essential for the reasonable analysis and statistical interpretation of stratigraphic engineering characteristic index data. Based on grain size,¹⁴ C,and sporopollen analysis data of sediments in the ZK2 drilling core of Lake Liangshanpo,the sedimentary environment of soft clay in the Liangshanbo area was restored under the guidance of Integrated Stratigraphy theory. These sediments were deposited in disturbed deep-water lakes during 750 to 1200 AD. Concurrently,the soft clay of Lake Liangshanpo has been reclassified from the Heituhu Formation to the Baiyunhu Formation through multiple stratigraphic divisions and correlations. Based on the test data and in-situ test results of 54 soft soil samples from 18 drilling holes in three areas of Lake Liangshan,combined with the engineering characteristic index data of the soft clay from another five projects in Liangshan County,the research and analysis found that,generally,the engineering characteristics of the soft clay in Lake Liangshanbo area were between silt or silty soil. It exhibits characteristics such as a large void ratio,high liquid limit,high compressibility,low shear strength,low permeability,and medium sensitivity,making it vulnerable to disturbances. Through the difference analysis of physical and mechanical indexes of soft clay in three areas of Lake Liangshanbo,it is pointed out that the sedimentary environment and mineral composition of sediments determine the engineering properties of soft clay in Lake Liangshanpo. Finally,compared with other typical lacustrine soft clay,the soft clay of Lake Liangshanbo has higher water content,a higher liquid limit,and lower shear strength. It also exhibits stronger expansibility and structure due to containing more hydrophilic clay minerals and having a larger porous sheet structure. These aspects should be given attention in future research and construction.