Abstract: Since the load of hydraulic turbine is random, the load spectrum is an important basis for design of hydraulic turbine, Many researcher intended to obtain stress spectrum by researching the pressure spectrum acted on the runner blade by means of the two dimentional flow theory or the three dimentional flow theory in our country, but they have not got the load spectrum that can be applied to engineering. According to field operating stress measurments, the operating stress of runner blades increase as the power of hydraulic turbine is raised, and the mean stress of maximum principal stress linearly dependent on the power of hydraulic turbine with the same head, Besides, we discovered that the power of francis turbine follow weibull distribution by investigating, counting and analyzsing the power of representative hydraulic turbine, Therefore, the operating stress distribution of blades can be calculated from the power distribution and then the load spectrum of hydraulic turbine can be obtained, this is a new economical and effective compiling way of hydraulic turbine load spectrum.