【Objective】To find a water efficient technique using underground drainage pipes to wash off soil salt is an issue that has aroused attention from scientists all over the world, because such a technique would make great valuable contribution to agricultural production and economic returns, especially in regions that have large areas of saline alkali soils. 【Method】 In this paper, a field experiment was conducted with drainage pipes, 50 mm or 90 mm in diameters,buried 0.6 m, 1.0 m or 1.4 m deep in the field under drip irrigation to explore effect of the usage of drainage pipes on soil salinity, relative to diameter and burial depth of the pipe. 【Result】 The experiment shows that desalinization effect of two rounds of drip irrigation varied from soil layer to soil layer. The effect was the highest in the 0~60cm soil layer, lowering the soil salt content down below 12g kg^-1 or to the moderate salinization level, but the effect was not significant in the soil layers below 100 cm. Drainage pipes buried at 0.6m in depth were higher than those 1.0 and 1-4m in depth in desalination effect, reducing soil salt content by 14.34 g kg^-1 in total, or by13.32 g kg^-1 as compared with CK, field without using drainage pipes Pipes buried at 1.4 mhad no significant effect on soil desalinization.The pipes different in diameter varied in desalinization effect. Pipes 90mm in diameter were much higher than those 50mm. The effect of pipes 50 and 90mm in diameter varied with burial depth, being in the range of 20.69%~30.20% and 34.59%~57.04%, respectively. 【Conclusion】In the fields with drainage pipes90mm in diameter buried 0.6m in depth, two rounds of drip irrigation reduced soil salinization in the 0~60cm soil layer to the mild salinization level (3~6 g kg^-1), indicating that the technique is high in desalinization efficiency and applicable to the regions of salt-affected soils in Xinjiang. And the findings in this paper may serve as scientific basis for choice of diameter and burial depth of drainage pipes in application of the technique.