By manipulating the Sr:Fe ratio, we have successfully controlled the formation of crystalline phases in Sr-Fe based OCs. Our study sheds light on the distinct functions of these phases in facilitating the simultaneous production of syngas and CO with high efficiency. A set of OCs based on Sr-Fe were produced through the use of ball milling, denoted as SrxFey. The labels x and y corresponded to the mole ratio of SrO and Fe₂O₃, respectively. The introduction of Sr into the system has the effect of reducing the oxygen transfer capacity and regulating the activity of lattice oxygen reduction, while simultaneously promoting the rate of lattice oxygen recovery. This leads to the manifestation of exceptional ethanol reforming capabilities in Sr1Fe2 at a temperature of 800 °C, as evidenced by a high carbon conversion rate of 96.07% and a correspondingly high syngas yield of 0.29 Nm³/kg OC. Furthermore, the Sr1Fe2 exhibits a noteworthy capacity for CO₂ decomposition (0.14 Nm³/kg OC) and displays commendable cycling performance. The prepared OCs yield crystalline phases that are primarily composed of SrFe₁₂O₁₉ and Sr₄Fe₆O₁₃, with x:y ratios ranging from 1:1 to 1:6. As the cycles proceed from the 2^nd to the 30^th, the dominant crystalline phase transitions towards Sr₄Fe₆O₁₃. This is due to the greater energy barrier for the CO₂ oxidation reaction exhibited by surface SrFe₁₂O₁₉ with oxygen defects (0.52 eV), which prevents Sr₄Fe₆O₁₃ from regenerating in the CLR-CS process.