According to project experience in Beijing Railway underground project, the changing cutter and welding techniques with high pressure of slurry shield under deep water-rich sandy gravel stratum were summarized. There were two main technologies. One is to choose an appropriate position and an appropriate working pressure for making a good previous preparation to ensure the stability of tunnel face. The other is the replacement and grouting of high-concentration slurry, which avoided the gas escape effectively. During the repair welding, we successfully realized going into the excavation chamber with high pressure for more than 250 times, and the working pressure rose from 0.9 bar(1 bar=100 kPa) to 2.8 bar with no accident.