Abstract: The leakage of oil,gas and water owing to the pipe cracking will usually have an important impact on the surrounding environment,and the forecast become relatively difficult because of the pipe concealment and the problems finding' hysteresis quality.At the same time,the sudden pipeline rupture leakage can lead to the change of the geological environment,which affects the mechanical properties of the infrastructure,and has a direct threat to the project safety.At present,the influence degree of the sudden leakage flow size to the subway tunnel is not accurate conclusion.This paper to Harbin metro construction,researches the method about looking for the source of seepage caused by break of the pipeline,and analyses the underground line leakage causes the influence on the ground surface settlement,tunnel vault settlement,and clearance convergence,according to the field measured data.