Abstract: Taking the Yangtze Petrochemical Company-Yangzhou Petrochemical Park Olefin Pipeline as an example, the factors in environmental pollution and safety risk were analyzed, and effective methods to deal with waste gas, waste water, solid waste and noise were proposed. The construction of whole project was under the relative industry standards and codes. Improving design coefficient, selecting high-quality steel pipe and coating is necessary to assure pipeline safety. Determining reasonable safety interval of pipeline is suitable to eliminate the inconvenience for persons and facilities. Two pipelines were designed to the laying-in-one-ditch (the propelyene pipeline was laid at the bottom of ditch, the ethene pipeline was laid at the top of ditch, the longitudinal net space of the two pipelines was about 1.7 m and the vertical net space of the two pipelines was about 1.0 m). Construction links in welding, inspection, pigging and hydrotest were under a closed monitoring. RTU block valve chamber was set up to avoid the pollution and economic loss in case of an accident. Key factors and measures during pipeline operation are summarized.