A moistening salt-displacing tube and a local desalination method thereof for saline and alkaline lands. Saline and alkaline lands are main cultivated land reserve resource in China. However, because saline and alkaline in said lands have toxicity and stresses induced harms to crops, said lands need to be treated before use for farming. The current available common methods for treating saline and alkaline lands at home and abroad are various, such as physical methods, chemical methods and biological methods, but effects of the methods are not ideal. The moistening salt-displacing tube comprises a semi-permeable membrane moistube (1) made of a high-molecular material. One end of the moistube is closed and the other end is connected with a tee joint (3). The moistening salt-displacing tubes are buried in the ground; the tee joints of the moistening salt-displacing tubes are connected by means of water pipes to form an irrigation network; and then plants are planted in a desalinated area produced by the moisteni
