Seagrass cottage is a unique rural cultural heritage in northern China. It has significant protection value. However, with the increase of the price of seaweed, the maintenance cost of the roof of seaweed houses is getting higher and higher, which creates a contradiction between cultural protection and economic benefits. I formulated a set of principles based on a series of view analysis. Dividing the village into important area and unimportant area, and then dividing the important area into strong control area and weak control area. Implementing different control schemes for different levels of areas. Finally reach a balance between cultural protection and economic benefits.