The invention relates to landscaping, in particular to a lawn green belt with low construction cost and good greening effect. The lawn green belt is characterized in that an unshaped lawn egg is arranged in the soil to be taken as a bearing frame; the lawn egg is an egg-shaped substance which takes construction wastes such as bricks, tiles, ceramics or building blocks, and the like as raw materials and is formed by means of firing or extruding; and the construction method of the lawn green belt comprises the following steps of: producing the lawn egg, preparing a base material, finishing a base and growing grass seeds. The lawn has the multifunctional lawn egg, is supported by the soil, protects growing points of the lawn, leads the growth room of roots to be large, has a multihole lawn egg frame system, leads green soil of the lawn egg not to be hardened, leads the green soil to be completely (100%) covered by green, is simple in maintenance, is low in management cost, has long service life, reduces the repeated construction cost, and the like.