Abstract: The nozzle of wet spraying machine is not only the direct component that forms the working condition of concrete jet, but also the key part to guarantee that concrete gets best kinetic energy and jet impact. The general index used for evaluating mine concrete wet spraying machine nozzle is put forward. The flow field of the SPB7-T wet spraying machine nozzle is studied by numerical simulation with Fluent software. Mixture static stress nephogram, single phase velocity contours and the volume fraction contours of nozzle exit phase are analyzed in nozzle flow field. The results show that the static pressure of mixture and velocity of each phase increase along the moving direction of concrete. There is a velocity slip between high pressure air and concrete . The air mixing uniformity is as high as 0.85 in the nozzle exit. The tests show that the resilient rate of the nozzle used for SPB7-T wet spraying machine is 9.993%, which proved the correctness of the simulation. The results provide a theoretical basis for future improvement and optimization.