Abstract: Wind turbine blade dynamic characteristic under different icing condition was simulated with experiment method. Blade-icing state parameters, which include the beginning parameter of icing areas, the length parameter of icing areas, and relative icing-thickness parameter, were defined. An experiment test rig for wind turbine blade vibration testing under iced condition was constructed based on artificial environment laboratory and modal analysis system. The modal of simulated turbine blade under different icing condition was analyzed, these characteristic value index of wind turbine blade icing parameters are extracted from the curvature mode parameter, and the icing status of simulation wind turbine blade was diagnosed by the characteristic value index, which is obtained from test. All the results of simulation and test show that the wind turbine blade ice diagnosis theory method and technology are correct and feasible.