Abstract: The tunable phase array with hexagon-lattice and round cell was designed and fabricated by use of periodically poled LiNbO3 crystal. Theoretical and experimental researches on the Talbot effect diffraction of phase array were presented. The simulated and experimental patterns of near field diffraction under various phases different and fraction Talbot distance were obtained. The results of experiment agreed with the results of the theoretical researches well. Average intensity of the selected area in diffraction field was calculated to get the relative intensity curves versus phase difference and distance. The effects on the intensity distribution of near-field diffraction from phase difference and Talbot distance were revealed.