With the rapid development of national economy in our country, the demand of oil and gas, as a representative of the major energy, continued to increase, and the security risks of long distance oil and gas pipelines also caused people's attention. Especially, the pipeline leakage deflagration happened from time to time in recent years, which caused not only great economic losses of the people's lives and property, also caused the ecological environment pollution and destruction. Therefore the leak detection of intelligent and efficient positioning method was applied to oil and it was critical for gas pipelines in a timely manner to prevent secondary disasters. The main cause of pipeline leak was analyzed, several kinds of leak detection methods used on the pipeline at present were summarized, and the method of negative pressure wave and flow balance method was dopt in crude oil pipeline leak detection experiments. The experimental results showed that the method could monitor oil pipeline leak in real time, especially small slow leakage, meanwhile could accurately locate the leak point.