Abstract: Sand mixing measures can change the mechanical composition and texture of soil, thereby improving the efficiency of fertilizer utilization. The surface sand mixing in irrigation area can effectively solve the problem of soils with high silt content. This study explored the water-salt transport mechanisms of heavy saline-alkali soils with different contents of sand. Laboratory soil column experiments were carried out to compare the effects of different sand ratio on infiltration characteristics and water-salt transport under continuous distilled water irrigation. The soil samples were taken from 0-40 cm abandoned heavy saline-alkali farmland in Bayannur City of Inner Mongolia, China. It was located in Hetao irrigation area. In the laboratory experiments, a total of 16 treatments were set up: CK (without sand), S1(2%), S2(4%), S3(6%)…S15(30%). The results showed that: 1) With the increase of sand ratio at the surface layer of soil, the cumulative infiltration and the rate of wetting front were increased at the same time. Compared with the treatment of CK, the steady infiltration rate of soil increased by 1.1, 1.3, 1.5, 1.8, 2.1, 2.3, 2.7, 3.1, 3.6, 4.1, 4.5, 5.1, 5.7, 6.2 and 6.8 times, respectively. It indicated that the steady infiltration rate of soil increased significantly with the increase of sand mixing ratio. When the sand mixing ratio was 18%-24%, the stable infiltration rate was 0.065-0.091 mm/min; when the sand mixing ratio was 26%-30%, the stable infiltration rate was more than 0.1 mm/min, and the water holding capacity of soil was low. 2) The mean soil moisture among treatments was significant different (P<0.05) at 7, 11 and 15 days, the rate of water infiltration could be increased by increasing the proportion of soil sand, and a large proportion of sand would reduce the water holding capacity of soil. 3) When the sand-mixing ratio were less than 24%, the total salt content of the soil at day 7 was significantly different among treatments (P<0.05). The total salinity content at day 3 was 21.95-73.38 g/kg in 30 cm soil layer, showing a decreasing trend. 4) the Kostiakov model could well fit the infiltration process of soil water in this study. The empirical coefficient in Kostiakov infiltration model showed a significant increase trend. Its change range was between 4.011 and 15.443 mm/min, which indicated that the average infiltration rate during the first period was increased when sand ratio was increased. The effects of adding sand in soils on increasing soil water infiltration was obvious. Therefore, the measures of mixing sand in the surface layer of heavy saline-alkali farmland would be an effective way to alleviate soils salinization.