Abstract: In order to promote high-yield and high-quality forage and scientific management of water and fertilizer in Xinjiang. The Huayouza 62 variety of rapeseed was used as the test material to conduct different water-nitrogen coupling treatments. Three different irrigation levels were set: 3 000 m~3·ha^-1（W1）, 3 750 m~3·ha^-1（W2）, and 4 500 m~3·ha^-1（W3）, three different nitrogen application gradients were set: 121.5 kg·ha^-1（N1）, 142.2 kg·ha^-1（N2）, and 162.9 kg·ha^-1（N3）. Through random combination, nine treatments were carried out in total. The accumulation and distribution of dry matter in forage rape under different treatments were analyzed to select the optimal treatment most conducive to increased production of forage rape. The results showed that, the accumulation of dry matter in forage rape increased with the increase of irrigation amount. The accumulation of dry matter under the W3N3 treatment increased by 47.70% and 108.62% compared with the W2N3 treatment and W1N3 treatment, respectively, and the yield increased by 9.77% and 74.02%. Under good water conditions, dry matter accumulation was positively correlated with nitrogen application rate, but under drought stress, dry matter accumulation showed an increasing and then decreasing trend. In terms of dry matter distribution, the proportion of stem biomass increased gradually and the proportion of leaves decreased gradually with the progression of the growth period. It demonstrates that under the condition of this study, the high-water and high-nitrogen treatment of W3N3(4 500 m~3·ha^-1 and 162.9 kg·ha^-1) is more conducive to dry matter accumulation of forage rape, through which more biomass can be obtained.