当鱼类资源通过常规水轮机时会不可避免地受到损伤。受伤和死亡的鱼类会对水域造成污染，从而制约了水电工程的生态发展。针对鱼类下行过坝的措施及存在的问题，笔者介绍了鱼类通过水轮机流道下行时可能受到的伤害机理，主要分为机械、压力、剪切力和空蚀四种。鱼体的损伤程度与鱼体的种类、尺寸、进入水轮机系统的方式等因素有关。本文根据过鱼损伤机理，提出目前鱼类友好型水轮机设计的主要思路，阐述了传统的水轮机进行鱼类友好设计的准则和典型的鱼类友好型水轮机的设计理念。

Fish suffers inevitable injuries when passing a common hydraulic turbine. Injury and mortality of fish will cause pollution to the water. This will restrict the ecological development of the hydropower project. Aiming at the measures for downstream passage of the fish and existing problems, four kinds of injury mechanisms, namely, mechanical, pressure, shear force and cavitation injuries, are introduced in this paper. The injury degree of fish is related to the type and size of the fish body and the way to enter the hydraulic turbine system. According to the injury mechanisms, the main idea of the design of a fish-friendly hydraulic turbine is put forward. The criteria for designing a conventional fish-friendly hydraulic turbin and the design philosophy of a typical fish-friendly hydraulic turbine are expounded.