The rainfall in western Henan province is low and dislocated from the wheat season, which severely limits the dry matter production and yield formation of wheat, resulting in low and unstable yields. In recent years, many fields in dry farming areas can achieve limited irrigation because of high-standard farmland construction, but still cannot meet the full irrigation conditions. Appropriate irrigation is an important way to promote wheat dry matter production to increase wheat grain yield, while the suitable irrigation to stabilize or increase wheat yield under limited irrigation conditions is still unclear. Therefore, this experiment explored the effect of timely irrigation on dry matter accumulation in different canopy layers and yield of winter wheat, and provided a scientific basis for achieving high wheat yield in dry farming areas. Field trials were carried out in Mingda Village, Xiaolangdi Town, Mengjin District, Henan Province in 2020-2021 growing season. Two water treatments were designed, namely no irrigation (W0) and timely irrigation (W1). Water content in 0-40 cm soil was replenished to 85% under W1 treatment when it was lower than 55% at the first time. The tested cultivar was Luohan 22, and the rotary tillage was applied with 120 kg·hm-2 of N fertilizer, 90 kg·hm-2 of P2O5 (12%) and 60 kg·hm-2 of K2SO4 (50%). Dry matter accumulation in wheat plants at anthesis, mid grain filling stage, and maturity from 0-30 (0-30 cm), 30- (30 cm to the union of stem and spike), glumes (spike axis and kernel husks) and grains (only at harvest), as well as grain yield and its components at maturity, was measured. Compared with W0, shoot dry matter accumulation in W1 treatment was significantly increased by 54.09%, 40.99% and 64.59% at anthesis, middle grain filling stage and maturity, in detail, the dry matter accumulation in the portion of 0-30, 30- and spike were increased by 34.55%, 94.31% and 53.14% at anthesis, as well as 23.37%, 92.93% and 23.15% during the middle grain filling stage, and 17.95%, 125.26% and 67.36%, respectively. Compared with W0, the pre-anthesis dry matter translocation in the 0-30 portion in W1 treatment was significantly increased by 8.47%, but significantly decreased by 9.55% in the 30- portion, and the contribution of post-anthesis dry matter accumulation to grain was increased by 3.25%. Compared with W0, the spike numbers and the grains per spike in W1 treatment were significantly increased by 42.87% and 42.35%, and thus the yield was significantly increased by 77.40%. In couclusion, timely irrigation can significantly increase the dry matter accumulation in different canopy layers of wheat plants, thereby increasing grain yield through significantly increasing the spike numbers and the grains per spike, which was an alternative way to increase yield of wheat under limited irrigation production conditions.