The invention discloses a construction method of slope vegetation. The construction method includes following steps: treating base layers on the surface of a slope and at the top of the slope, enabling manpower to cooperate with an excavator to level a site, repair the slope and compact a foundation, rolling to compact the base layer at the top of the slope to enable compactness of the foundation to reach design requirements so as to reduce wall settlement, and setting up an ecological bag and a three-dimensional drainage connecting buckle placement position nearby; after surface treatment inspection of the base layers on the surface and at the top of the slope is qualified, starting to form trenches, wherein depth of each trench is 20cm while width of the same is 30cm, and each trench longitudinally extends to the downstream from the top of the slope to the surface of the slope. By the construction method, edges of riverways and edges of mountains can be made more stable to be unlikely to cause landslide due to rain washing.