This article presents a study of water-heat coupled problems of frozen soil along the Mohe-Daqing crude oil pipeline with thermosyphons. It is known that the Mohe-Daqing pipeline goes through four different kinds of frozen soil classified by ice content in soil. To determine the region with high tendency of permafrost thawing, the temperature field and water content field of the four types of frozen soil were first investigated in this paper. Taking freezing and thawing risk, typical geological condition and other factors into consideration, the soil temperature field of pipeline located at the permafrost swamp area was calculated numerically. Comparative study was also carried out for soil temperature field with and without thermosyphons to investigate the cooling effect of thermosyphons. It is evident that thermosyphons have great influence on temperature drop of permafrost, and this influence is especially magnificent in winter. In contrast to soil temperature without thermosyphons, installing the thermosyphons could reduce the soil temperature right beneath the pipeline by approximately 4 degrees C. Numerical results, which have been validated by field data, are of great guiding significance for construction and operation safety of pipelines buried in cold regions.