Abstract: Influencing factors on contamination growth, distribution and contaminated volume for long-distance oil product pipelines under normal operating conditions are analyzed and operation data for batch transportation of oil product pipelines are summarized. Based on contamination blending treatment, methods to comprehensively utilize oil product resource and quality potential of unloaded oil product in pumping stations along oil product pipelines and decrease contamination unloading and cutting treatment for contaminated volume at terminal of trunk lines are presented. The methods include that mixed contaminated tail produced in trunk lines can be properly unloaded at pumping stations over the pipeline, trunk line's contamination can be offtaken by branch lines, partial contamination can be unloaded at pumping stations over the pipeline and contamination at terminal station should be classified into contamination section with different density proportion, etc. These methods have been used in contamination cutting treatment and remarkable results have been achieved in Southwest Oil Product Pipeline, which can effectively decrease the pressure of contamination treatment for the whole pipeline.