Abstract:In order to investigate the vibration response of the vertical pipe under internal and external flow during the drilling and machinery production, taking deepwater drilling pipe in the South China Sea as the research object, based on similarity theory, a vibration response test platform for both single and double pipe with internal flow was constructed with consideration of the gravity similarity principle, and experiments with vertical pipe under both internal and external flow were performed. The results show that the vibration frequency of the pipe is reduced due to the internal flow;moreover, with the increase of internal flow velocity, the vibration frequency decreases;the outflow is the major contributor for causing the vibration of the underwater pipe, the higher the outflow velocity is, the more diverse response is participated in vibrations;the vibration response is significantly reduced when the spacing ratio of the double pipes arranged in series is under 4.