A apodization method with Tukey-window function for digital hologram of particle-field was presented, whose energy transmission is relatively high and the sidelobe peak is relatively low as well as the sidelobe roll-off rate. The principles of in-focus position measurement and digital hologram apodization using Tukey-window for particle were analyzed. The digital holograms of little monolayer particle-field attached on glass surface were recorded, and the apodized holograms adopting Tukey window were reconstructed. The experimental results show that the reconstructed images after digital holograms apodization do not have black-and-white interference fringe, increase contrast and have more clear particle image. The reconstructed particle image located in the fringe field is nearly submerged by the apodized aperture. With increasing the apodization parameter of the window function, the more accurate position of the particles in-focus can be gained, and the measurement precision of particle in-focus position is improved.