Abstract: This paper focuses on the special technical characteristics of helicopters, especially on the flight principle that differs from fixed-wing aircrafts, complex aerodynamics and structural dynamics, and demanding weight design, etc. Technical difficulties in aerodynamics, vibration and noise, ground/air resonance, crashworthy, safety, and weight control, as well as the underlying physical mechanisms and solutions are also expounded. Based on the analyses and study about development directions of helicopter technology in the world, it is proposed that future helicopter technology will focuses on high-speed, green, intelligent, unmanned, and safe flight. Combining the present situation and future trend of the helicopter technology development in China, three important directions for the future development of helicopter technology in China are put forward. These directions are advanced rotor blade and airfoil design, smart rotor, and high-speed helicopter. The scientific connotation and possible solutions of key technologies for the above directions are further proposed, which can hopefully provide a good idea for the future development of Chinese helicopter technology.