This invention involves a wind turbine rotor. A rotor reinforcing device (10) comprise a center connecting device (40) which are fixed on the rotor hub (6); and long and thin blade reinforcing members (21, 22, 23, 24, 25, 26) which are connected to center connecting device (40) and corresponding rotor blade (1). The rotor reinforcing device (10) has the advantages of having a light weight and a simple structure. With the help of the center connecting device (40), the rotor can be easily reinforced. This invention also involves a rotor, a rotor-based ocean current turbine, a rotor-based tidal turbine and a rotor-based power generator.