Abstract: Upon commissioning, the 1st and 2nd Xingang-Dalian Crude Oil Pipelines have experienced several rounds of technical reconstructions and formed a unified hydrodynamic system with the Tieling-Dalian Crude Oil Pipeline, with operations much more complicated than independent operation of individual pipelines. With consideration to field applications, the paper reviews operations without slack flow during transportation of Russian Oil to Xingang Tankfarm through the 2nd Xingang-Dalian Crude Oil Pipeline, rules in operations of the 2nd Xingang-Dalian Crude Oil Pipeline to transport Russian Oil to the West Pacific Refinery and impacts of tank change-over operations in Dalian Petrochemical Terminal Station to export pressures of the 1st Xingang-Dalian Crude Oil Pipeline. In addition, pressure data of the 1st Xingang-Dalian Crude Oil Pipeline in "6.30 Accident" are analyzed to determine operation rules and on-site operation techniques by using uniformed hydrodynamic system. The research results can provide necessary guidance for safe operation of the 3 pipelines and better management and operation of the hydrodynamic system.