Abstract: In this paper, the flow characteristics and laws of fluids inside cryogenic corrugated flexible pipes were analyzed to ensure that a large amount of liquefied natural gas (LNG) can be transported quickly, continuously and efficiently in this kind of pipe. A theoretical analysis method of equivalent friction resistance was provided to investigate the flow characteristics of fluids inside corrugated flexible pipes. A numerical model for internal fluids with consideration of helical structure characteristics was established based on the property parameters of LNG. The flow laws inside different corrugated pipes were simulated by using the software Fluent. And the flow characteristics and sensitivity of C-shape corrugated pipe with different structural parameters were comparatively analyzed. It is shown that the helical structure can increase flow capacity effectively. And in actual engineering, cryogenic corrugated flexible pipes with different corrugation shapes are quite different in term of the transportation performance. The research results provide the meaningful reference for the structural design of cryogenic corrugated flexible pipe used for LNG marine transportation.