With the excavation of foundation, when the earth pressure of foundation reduced to a certain extent, the head pressure of confined water will be greater than float gravity of soil at the bottom of foundation pit associated with piping formation and side gushing and so on, resulting in floating and cracking of soil. Based on deep confined water partition technique, according to the characteristics of the foundation of Shanghai Sanzhi Sheraton Hotel, application effect of ultra-deep cement-soil mixed pile in deep confined water partition project were analyzed and discussed, which could be the reference and guidance for the similar projects in future.