Abstract: As for the rock ground with large overburden and developed rock fisser water as well as the mixd ground with rich water and airtightness, the blow-out event often occurs due to a large shield load and quick wearing of cutting tools when conventional full earth pressure driving mode is adopted, which results in low efficiency and poor-quality simutaneous grouting. The definition of the“air pressure balance”mode and its advantages and disadvantages are presented based on practical experience with the Guangzhou Metro lines 1, 2, 3 and 13Additionally, key techniques for“air pressure balance”driving mode are studied, secondary risks concerning this driving mode are analyzed and measures for prevention and countermeasures for emergencies are given in this paper.