In order to investigate the characteristics of air-velocity field of disk fan used in orchard sprayer, a turbulence model by means of the standard sub-model with appropriate boundary condition was developed and 3-D steady state of air-velocity field of single and double fans was simulated and verified. The results showed that in the distance of 1m to 3m from the double fans center, the velocities of the center region were lower than the both sides, but in the distance of 3m to 5m, the air-velocity distribution of double fans was uniform. The results of comparison showed that the trends of simulated and measured curves were coincident, the correlation determination (R2) of single and double fans were 0.8044 and 0.7957, respectively. The model could accurately predict air-velocity distribution pattern. 