The scientific judgment of the three-phase superposition "the new normal of economic development and the transition of economy from high-speed growth stage to high-quality development stage. The stage of high-quality development is logically consistent with the judgment of the "three-phase superposition" and the new normal of economic development. The stage of "three-phase superposition" and the new normal of economic development are more to clarify the new features of the periodic changes of economy, while the stage of high-quality development is not only a generalization of the development stage, but also reflects the strategic and value orientation of development. High-quality development is the development that can well meet the people's increasing needs for a better life and embodies the new concept of development