Using ANSYS CFX11.0, this paper conducts full three-dimensional numerical simulations of the cavitation behavior of an axial pump with turbulence model of standard k-ε, homogeneous multiphase model, and Zwart-Gerber-Belamri cavitation model. The head performances of cavitation of an axial pump are obtained. Simulated performance of the axial pump agrees with the measured data. Location of cavitation and evolution of cavity in the axial pump and the relation between the cavitation behavior and performance of axial pump under the different operations are analyzed.