Poly-gamma-glutamic acid (γ-PGA) is a new type of environmental friendly polymer material. It has good water absorption, super adsorption and biodegradability, and has great potential for water saving. In this paper, the effects of different γ-PGA application rates (0, 1%, 3%, 5%) on soil water infiltration and soil water and salt transport were studied through indoor soil column simulation experiments. The results showed that with the increase of γ-PGA application rates, both the infiltration capacity and the wetting front movement velocity of soil decreased, and the stable infiltration rate also decreased significantly. Compared with the control, the cumulative infiltrations with 1%, 3% and 5% γ-PGA applied decreased by 16.22%, 40.34% and 54.72% respectively. The advancing distances of wetting fronts decreased by 17.74%, 52.32% and 61.61% respectively. The simulation results of two kinds of infiltration model parameters showed that the absorption rate (S) in Philip formula decreased from 1.669 to 0.854 when the amount of γ-PGA was increased. The empirical coefficient (K) in the Kostiakov formula reduced from 0.855 to 0.792. The empirical index (β) increased from 0.356 to 0.480, and there was a linear negative correlation between the amount of γ-PGA application and the parameters of S and K. The slopes were -16.583 and -1.195 respectively. The application of γ-PGA changed the water and salt distribution in soil profile.With the increase of γ-PGA application, the water content of surface soil (0-10 cm soil layer) increased, while that of deep soil (below 10cm soil layer) decreased, but the change trend of the salinity in soil profile was opposite to that of soil water. This indicated that γ-PGA could reduce the infiltration of soil water and significantly increase the water holding capacity of soil. At the same time, γ-PGA could significantly improve the salt leaching in the soil surface. This study provides a theoretical basis for the use of γ-PGA in water saving and removal of soil salt as a soil amendment.