Abstract: The simple horizontal distribution of farmland landscape in Haihe lowland plain is the reason that farmland landscape is losing its ecological stability.Based on this problem and guided by the landscape ecological principles and methods, a study was conducted to indicate that the diversified crop landscape reduces the incidence of plant disease and insect pests and improves field microclimate. The study makes clear that the relationship between the landscape unit standard and composition of landscape elements with insect pests incidence.The results provide a scientific basis for better management of the farmland landscape ecology and its ecological stability.