This paper presents a review of large-scale testing for wind turbine nacelles

i.e. sophisticated systems designed for operation under extreme loads and harsh environmental conditions. Given the critical need for high reliability

comprehensive developmental testing is paramount. As onshore and offshore wind power scales up

testing methodologies are continually evolving. This article first delineates the purposes and fundamental content of nacelle testing. It then surveys the current status of international ground-based public test facilities for large-power wind turbine drivetrains

providing a comparative analysis of their characteristics

including rotor torque loading

non-torque loading

and electrical grid simulation capabilities. A detailed introduction to a 25 MW wind turbine nacelle test bench at China Electric Power Research Institute is provided. The 25 MW test bench

integrating a dual-motor drive

Yoke loading

90 MVA grid emulation

and a digital twin

has successfully certified a 26 MW turbine

demonstrating world-leading performance. The paper concludes with a forward-looking perspective on the future of public ground testing systems for large-scale wind turbine nacelles.