In this present investigation, the effects of nitrogen fertilizer rate and post-anthesis soil water content (SWC) on photosynthetic characteristics and yield of wheat was tested under proof-rainfall pool culture condition. The results showed that soil and plant analyzer development (SPAD) value, photosynthesis rate, PSⅡ potential activity (Fv/Fo) and PSⅡ photochemical efficiency (Fv/Fm) were increased with the increase in nitrogen fertilizer rate under the same SWC. Moreover, increased nitrogen fertilization benefited the increase of spike numbers per hectare. However, over high (300kg/hm2) or over shortage (150kg/hm2) nitrogen fertilization was unfavorable to the increase of kernel number per spike and 1000-grain weight (TGW), and in turn it could lead to yield decrease. Under the same nitrogen fertilizer rate with SWC (60%-70%) after anthesis, SPAD value, photosynthesis rate, Fv/Fo and Fv/Fm showed the highest, whereas the treatment of SWC (40%-50%) was the lowest and the treatment of SWC (80%-90%) was in the middle, meanwhile, over high SWC (80%-90%) or over low SWC (40%-50%) after anthesis could cause the decrease of kernel number per spike, TGW and final yield under the same nitrogen fertilizer rate. It can be concluded that both high and low SWCs after anthesis can cause a decline in photosynthetic characteristics in wheat flag leaves, whereas proper nitrogen fertilization can improve photosynthetic characteristics in flag leaves, increase kernel weight and promote yield in wheat.