Abstract：The representative quick mud in Huanghua Port，Shenzhen Port，Lianyungang Port and Tianjin Port，which are
the coastal ports in China，was tested in laboratory and the test results were analyzed，the vacuum preloading test of the quick
mud in Huanghua Port in a large indoor testing flume was carried out. The test results show that the amount and the type of clay
minerals are primary factors which impact the vane strength of quick mud，the decrement of water content and increment of
vane strength of quick mud in the process of soil improvement at Huanghua Power Plant have good correlation；Large-area ultra
soft soil improvement with the vacuum preloading method must be analyzed through field test.