The invention discloses an ecological stable governing method for a river lake sedimentary facies slope. The ecological stable governing method includes the following steps that soil layer recognitionand division and native species screening of the target governing slope are conducted; native species cultivation and fast-growing vegetation forming are conducted; field management is conducted; recovery of slope plant community species diversity and the water and soil conservation function is conducted; and population renewal and vegetation stability and sustainability are achieved. By means ofthe stable governing method, engineering measure input of cement, bricks and the like is not needed, the governing cost is greatly reduced, a community with native species as the main part can be built within 1.5-2 years, the vegetation coverage degree of the target governing slope ranges from 60%-90%, and the soil erosion amount of the slope is reduced to 20%-50% of the original soil erosion amount of the slope; and the built community adapts to the regional environment, and the community is a functional community which is good in species diversity, high in community stability and sustainability and high in soil erosion regulating capability.