To explore the effect of irrigation at the jointing stage on nitrogen (N) redistribution after flowering and productivity effects of water and N in winter wheat (Triticum aestivum L.), a 2‐yr field experiment was conducted between 2015 and 2017. Three irrigation regimes were designed as follows: rain‐fed (W0), irrigation at jointing and 7 d after flowering (W1), and irrigation at 7 d after flowering (W2). Compared with W2, W1 increased spike number, kernels per spike, and N and dry matter (DM) accumulation at flowering; delayed the senescence of flag leaves after flowering; increased the flag leaf photosynthetic rate, redistribution of N and DM from vegetative organs to grains in the middle and late grain filling stages, and grain yield; and decreased N and DM redistribution and grain weight during early grain development. This may be the reason why the N uptake efficiency and N productive efficiency were higher, whereas the productivities of water and N had no significant difference, and even water productivity was lower under W1 than W2. Therefore, on the basis of suitable water supply from jointing to flowering, achieving a high N and DM accumulation at flowering and high kernels per spike, if the grain development can be accelerated earlier and the redistribution of N and DM can be promoted, it is expected to further improve the productivities of water and N.