Abstract: Project general of Karamay-Urumqi Oil Products Parallel Pipeline and fracture accidents at 2 pipe sections during pressure test are introduced.Influencing factors in pressure test are discussed from pipe material strength/pipe body defects, high-frequency welding pipe manufacturing process and quality control of manufacturing process workflow.Possibility to result in pipe fracture is analyzed, and following factors, that is, test pressure exceeded the yield limit of pipe itself, lower environment temperature and water temperature, are rejected.While factors in welds quailty below standard, failure to inspect the pipe quailty in control link during manufacturing, incomplete mechanical property in pipe steel itself as well as propagating and cracking of pipe from its inner defects induced by yard pressure test and strength test are the possible fracture cause.And in final, the fracture accidents come down to management factor.