Abstract: In order to study the relationship between seepage stability of pressure tunnel and each of surrounding rock permeability coefficient,surrounding rock deformation modulus,geo-stress,lining type and thickness separately,a seepage-stress-cracking coupling numerical model for pressure tunnel internal water exosmosis was established.Analysis cases of different surrounding rock permeability coefficient,surrounding rock deformation modulus,initial geo-stress,lining type and thickness were programmed and internal water exosmosis calculations were carried out by using the above mentioned model.Using permeability rate and destroyed hydraulic pressure as the seepage stability index,parameter sensitivity analysis of surrounding rock permeability and deformation modulus,geo-stress and lateral pressure coefficient,lining type and thickness were conducted based on the calculation results.Effect degree of various factors on the permeability rate and destroyed hydraulic pressure of pressure tunnel were presented.The results presented herein can provide reference guidelines for the design of pressure tunnel and lining selection.