Inversion symmetry breaking in materials with strong spin-orbital interaction will induce novel phenomena such as Rashba effect, Weyl fermions and odd-parity topological superconductors. When this happens at presence of strong electronic correlations, its effects have not been well studied yet. Here, we show that it can dramatically changes the electronic properties by studying the mysterious hidden order phase transition in the strong spin-orbit-coupled correlated metal, Cd2Re2O7, where a tiny structure change with inversion symmetry breaking induces dramatic changes in its electronic properties. For this study, we apply the first-principle density functional theory plus dynamical mean-filed theory method and transport measurements. Our results show that the electronic correlations in Cd2Re2O7 derive mainly from Hund's couplings, and the correlation strength is significantly reduced after losing the inversion symmetry which is caused by enhancing the dynamical mean-field function through the splitting of Kramers degenerate bands. Our results can naturally interpret the electronic anomalies across the phase transition without any electronic orders.