The Pythagorean Frustum Unified System V12.0 represents a self‑consistent axiomatic framework that unifies macroscopic cosmic structure and microscopic particle physics without relying on external physical assumptions. Drawing on three core papers, this study systematically synthesizes the system across three interrelated dimensions: theoretical foundation, geometric mechanism, and empirical validation. The first paper establishes the full axiomatic architecture, defines fundamental entities including the Primitive One, Background One, and global operator, and rigorously demonstrates that 11 dimensions constitute the universe’s optimally stable boundary. The second paper elucidates the intrinsic three‑layer coaxial dual‑cone topology, introduces the principle of high‑dimension priority growth, and describes the closed evolutionary cycle of cosmic growth, aging, collapse, and self‑repair. The third paper employs authoritative open observational data from Planck, Gaia, JWST, LIGO, and CERN to conduct topological fitting, dynamic field validation, and macro–micro isomorphism testing, verifying the system’s logical closure and high fitting precision. Together, the three documents form an integrated academic chain: theoretical construction → mechanistic exposition → empirical confirmation, providing a novel paradigm for unified physics.