Abstract: Based on the theory of J integration in elastic-plastic fracture mechanics, and comprehensively thought of the elastic solution and pure plastic solution of J integration with cracking structure, the elastic-plastic fracture subject of ductile pipeline with cracking was analyzed in this paper. By analyzing the field fracture pipeline, it showed that the result obtained was identical with site failure data. Based on this research method, the critical failure pressure on Lunnan-Korla oil pipeline was analyzed in this paper, thus, a theory foundation was supplied for safety running of this pipeline at designed situation.