A　system　of　distributed　optical　fiber　sensor　has　presented　based　on　the　optical　fiber　sensor　technology　and　detected　the　oil　pipeline　leakage　using　Mach-Zehnder　optical　interferometer.　There　are　two　interferential　signals　from　sensor　and　reference　light　to　put　in　computer　has　been　analyzed　using　the　analysis　software　LabVIEW　of　National　Instruments＇　that　can　operate　for　the　cross-correlation　function,　then　compare　the　correlation　peak　to　obtain　the　disturbance　of　oil　leakage　location,　the　detection　precision　200m　at　around　50km　for　pipeline　in　the　high　speed　sampling　and　data　signal　processing　has　obtained.