Experimental investigations were carried out to study the rotating film cooling characteristics at different blowing ratios in a 1.5-turbine stage.The mainstream Reynolds number Reg is 1.6451×105 in the experiment.CO2 acts as a coolant with mainstream jet density ratio of 1.57.Turbine speed is 475r/min

and the rotation number is 1.901.The blowing ratio varies from 0.5 to 2.0.By using steady-state liquid crystal method

the results show that: (1) On pressure side

the film cooling efficiency and the film coverage increase

the deflection angle of film trajectory decreases with the increasing blowing ratio. (2) On suction side

the film cooling efficiency and the film coverage first increase and then decrease

the film trajectory has no obvious deflection angle with the increasing blowing ratio. (3) The curvature radius of jet flow affects the adhesion of film on the wall.