Optimizing the volute performance can effetely improve the efficiency of a centrifugal fan by changing the volute geometric parameter, so the Kriging model is used to optimize the volute geometric parameter. Firstly, Volute radius Rd, the radius of tongue r and outlet angle of the volute θ are selected as the optimization parameters of the volute, and Latin hypercube sampling is used to configure the initial sample points, the corresponding three-dimensional aerodynamic model under each sample point configuration is constructed. CFD software is used to simulate the efficiency value and total pressure of the centrifugal blower under each initial sample point configuration; Secondly, the Kriging surrogate model of initial sample point configuration parameters, efficiency value and total pressure of volute is constructed, the high-precision Kriging surrogate model is used as the fitness function of NSGA-II algorithm to get the optimal solution. The rationality of the above method is verified by optimizing the 9-19.4A type centrifugal fan volute. The efficiency of the optimized fan under working conditions is increased by 1%, and the total pressure under working conditions is not reduced.