Pipeline security is very important in oil and gas transportation. Traditional technology such as negative pressure wave detection, acoustic detection doesn’t match the need of pre-alarm. A fiber-optic distributed vibration sensor (FDVS) is proposed and investigated. It is found that the FDVS has the advantages of long sensing distance, high spatial resolution, high sensitivity, high reliability, etc. According to calculating the time delay of the two MZIs , the vibration can be located.