This paper proposes the "Meta-model of Existential Dynamics", aiming to construct a systematic ontological framework for describing the necessary constraints that any system must satisfy to maintain its existence. The model asserts that a system's stability stems from a continuous process of dynamic balance among three meta-constraints—Acquisition, Efficiency Seeking, and Continuation—across the two dimensions of Scale and Temporality. The core innovation lies in its non-teleological ontological stance, which reinterprets seemingly purposeful behaviors as emergent phenomena arising from these basic constraints. Through a rigorous case study of evolutionary theory, we demonstrate how classical scientific theories can be systematically reinterpreted through this framework. By offering a unified 'dynamic grammar' and a bridge between philosophy and empirical science, the model facilitates a unified understanding of phenomena.