Flexible pipe is one of the most important equipments applied for hoist and transportation in deep-sea mining. In this paper, the application requirements and status of flexible pipes are systematically proposed with respect to development mode, transmission medium and self-reliability in deep-sea mining. This is followed by the types and technical characters of four typical kinds of flexible pipes. In order to meet the requirements for deep-sea mining, technical route for developing flexible pipes used in deep-sea mining is proposed, and the technical challenges of flexible pipes are described including global application, section design, manufacture and test. Those may provide necessary technical references for developing the flexible pipe used in deep-sea mining in China.