Hybrid wheat is considered to be one of the main ways to greatly improve the wheat yield in the future, and population construction is an important factor affecting their yield heterosis formation. In order to clarify the effect of population regulation of hybrid wheat on source–sink systems, the two-line hybrid wheat variety Jingmai 6 was used to carry out relevant research in this experiment. The leaf area index (LAI) of Jingmai 6 showed an increasing trend, while the tiller-spike rate exhibited a downward trend with the increase of planting density. The total accumulation of dry matter at maturity increased with the increase of planting density, among which the relative proportion of dry matter pre-anthesis gradually increased, while that after anthesis gradually decreased. The sink capacity and spikes number of hybrid wheat were positively correlated with the grain yield. There was higher sink capacity, spike to leaf ratio and grain to leaf ratio under A2 and A3 conditions. With the increase of planting density, the hybrid wheat yield showed a unimodal curve, and A3 had the highest grain yield. Combined with the change trend of dry matter accumulation before and after anthesis, it was proved that suitable planting density was the key to obtaining high yield of hybrid wheat.
