Abstract: The study aims to explore the distribution of wheat root in mild and moderate saline alkali soil in the Yellow River Delta and analyze the coupling effect of water-fertilizer on root morphology and distribution of Wheat. The authors set four kinds of irrigation which were no irrigation, irrigation before sowing, irrigation before sowing and jointing, irrigation before sowing, jointing and seed filling, and four kinds of fertilization which were no fertilization, organic fertilizer, organic and inorganic compound fertilizer, inorganic compound fertilizer, to explore the coupling effect of water-fertilizer on root morphology and distribution of wheat of the saline soil in the Yellow River Delta. The results showed that the roots of wheat in saline alkali soil were mainly concentrated in 0-30 cm soil layer, and decreased with the deepening of soil layer. In this study, there was a significantly positive correlation of each root morphological index. Irrigation time and fertilization type had significant effects on the growth and development of wheat roots. The root vigor of wheat and root morphology treated with inorganic compound fertilizer and two-times irrigation were the best. Therefore, the distribution of wheat root in mild and moderate saline alkali soil was mainly concentrated in the top 30 cm soil in the Yellow River Delta, and jointing water and inorganic compound fertilizer could promote root development, and make good wheat root morphological structure.