A turbine for solar thermal power generation and a Brayton cycle are disclosed. The turbine includes a blade which has a cooling working medium inlet and a cooling working medium jet orifice. The blade is provided as a cavity with hollow interior; the cooling working medium inlet is located inside the blade; the cooling working medium jet orifice is provided on the blade surface on which is provided a spectral conversion coating; the spectral conversion coating converts heat on the blade surface into conversion characteristic band radiation which is radiation energy adjacent to cooling working medium characteristic band radiation of a cooling working medium. The turbine adopts a characteristic spectral coating and a jet cooling to enhance the cooling effect for a turbine blade and to improve the system efficiency of the Brayton cycle.