For hot crude oil pipeline,shut down,start-up and operation are based on the soil temperature around the crude pipeline.Only the distribution of the soil temperature was obtained accurately can make sure the pipeline operate safely and avoid condensing the pipeline.In pipelines laid in one ditch,hot crude oil pipeline temperature field was influenced by the cool products pipeline,so the temperature field of pipelines laid in one ditch was different from the single pipeline.On the crude oil pipeline and the products pipeline in China,the three-dimensional temperature field of pipelines laid in one ditch was carried out with the unstructured mesh and standard k-e model.Comparing the temperature field of pipelines laid in one ditch with the one of single pipeline,the effect of products pipeline on temperature field of crude pipeline was analyzed.