Abstract: Monitoring technology for long-distance pipelines at home and abroad mainly includes flowrate balancing method, real-time model method, statistical analysis method and negative pressure wave method. As for operation characteristics of products pipeline, this paper analyses the key points in negative pressure wave leakage monitoring technology, and carries out quantitative calculation for signal wave speed under batch transportation conditions, provides the qualitative description for signal change under multi-batch transportation, frequency regulating, etc, which gives description for main performances of monitoring system for leakage of products pipeline, that is, locating and alarming in a correct and timely way. It takes the combined monitoring method of sound wave-negative pressure wave as a solution to monitoring the leakage of refined oil pipeline, and provides the leakage detection principle and leakage monitoring process. The simulation test and field application results in Lanzhou-Chengdu-Chongqing products Pipeline show that this solution has a better, more stable and reliable effect, and all indexes satisfy the relative requirements.