The invention discloses a mixed flow type hydroturbine weight-bearing bracket fatigue life test and analysis method, which is characterized by comprising: determining a main weight-bearing bracket according to the structure form of a mixed flow type hydroturbine unit, measuring the strain at the surface of the weight-bearing bracket, ejecting the rotating part of the unit in a shutdown state, obtaining a strain value when the gravity of the rotating part of the unit is applied on the bracket, obtaining actual force applied on the bracket, carrying out strain measurement during a starting process, a load applying process, a load rejection process and a shutdown process, calculating the force applied on the weight-bearing bracket, counting the load-time processes of each working condition by using a cyclic counting method, counting the operating times of various working conditions, obtaining a bracket material S-N curve, and according to the working conditions, the load spectrum and the S-N curve, calculating the bracket fatigue life according to linear cumulative damage. According to the present invention, with the method, the actual force applied on the bracket can be rapidly and accurately measured, the fatigue life evaluation can be really and effectively performed on the weight-bearing bracket, and the weight-bearing bracket fatigue life analysis accuracy is improved.