Wind turbine blades are the core components of wind turbines, and their performance and status directly affect the operational efficiency and safety of wind turbines. In order to realize accurate monitoring and intelligent management of wind turbine blades, this paper proposes a digital twin system for wind turbine blades based on digital twin technology, which is able to construct a digital model in virtual space that is completely equivalent to the wind turbine blades, reflecting in real time the operational data and status of the wind turbine blades, and realizing on-line monitoring and predictive maintenance of the wind turbine blades.