Mulching with maize straw and planting winter wheat at high density can reduce soil evaporation and increase water use efficiency. In a study in North China, high mulch and high crop density together decreased soil evaporation, leading to better wheat performance. Normal density with high mulch had the lowest yield due to reduced soil temperature. Winter wheat yield and water use efficiency were highest with high density and low mulch, showing a 20.6% increase in yield and 21.9% increase in water use efficiency compared to normal density with no mulch. This approach maximizes water use efficiency for winter wheat in the North China Plain.