Mechanism Interpretation, Testable Predictions and Decisive Experimental Scheme of Quantum Entanglement Based on the Primon Substrate Model

This paper interprets quantum entanglement phenomena under the Primon substrate model. Based on three fundamental postulates, the model adopts a classical local physical framework and resolves the "action-at-a-distance" paradox of quantum entanglement. The measurement only reads the inherent symmetric properties of paired vibration units, without superluminal information transfer. This model differs from the local hidden variable framework discussed by Bell’s theorem. It further derives a testable unilateral non-symmetric stretching effect: the vibration unit propagating along the longer optical path undergoes self-structure stretching, while the unit on the shorter path retains its reference dimension. The stretching magnitude converges to a fixed physical upper limit rather than increasing linearly indefinitely. Three tiers of feasible decisive experimental schemes are proposed, including a high-precision benchmark scheme, an engineering-ready core scheme and a low-threshold preliminary test scheme. The model retains the mathematical framework of conventional quantum theory without numerical conflicts, and provides a causal physical entity mechanism. All predictions are open to experimental falsification. If future experimental data contradict the predictions, the author abandons this model.