In view of the problem that soft soil in the Yushan sea area is very developed and has a great influence on the engineering construction，we analyze the results of the soft soil geotechnical test in this sea area，including the influential factors such as physical and mechanical indices of the ③2 silty powder clay layer. Using mathematical-statistical methods and fitting the main indicators for correlation，we obtain the results which show that the layer has poor engineering properties and dispersion of conventional physical test indicators is small；the natural moisture content and pore ratio，liquid limit and plastic limit，plasticity index have obvious linear correlation characteristics；shear strength increases with depth，showing the rule of cross-slab in-situ test （in-situ）＞ straight shear fast shear＞ consolidation fast shear.