The effect of w(MgO) / w(Al₂ O₃ ) on the liquidity of the composite calcium ferrate (SFCA) binder phase inhigh-basicity sinter is investigated,focusing on three aspects:liquidity index,liquid phase formation temperature andmelting time. The results show that as the ratio of w(MgO) / w(Al₂ O₃ ) increases,the dissolution of Fe₂ O₃ into the SFCAmelt increases,the intensity of the SFCA diffraction peak increases,while the intensity of the Fe₂ O3 diffraction peakdecreases,thereby promoting the formation of SFCA. In terms of liquidity,high-aluminum systems tend to form highmelting-point ununiform phases and thus have poor fluidity,the medium-aluminum system exhibits optimal fluidity due toreasonable composition matching,the low-alumina system is less affected by proportional changes and has relatively stableliquidity. The liquid phase formation temperature generally increases with the increase of w(MgO) / w(Al₂ O₃ ),and theorder of temperature is high-aluminum > medium-aluminum > low-aluminum. The temperature at which the liquid phasebegins to form generally rises as w (MgO) / w (Al₂ O₃ ) increases in low and medium aluminum systems,with only adecrease in certain proportions. In high-alumina systems, the fluctuation is “ rise-decrease-rise”, which is related toviscosity and temperature changes before melting. The termination formation temperature rises in all systems,with the highaluminum system always having the highest termination temperature due to increased w(MgO) / w(Al₂ O₃ ) levels,whichreduces wettability and hinders the melting process. The temperature range between the termination temperature of liquidphase formation and flow temperature is highest when w (MgO) / w (Al₂ O₃ ) is 0. 4,indicating that the liquid phaseformation range is widest at this ratio,while an excessively high w(MgO) / w(Al₂ O₃ ) ratio inhibits liquid phase formationand flow. The melting time is shortest at 0. 3 in low-alumina systems and 0. 4 in mid-aluminum systems,in contrast,thehigh-alumina system is generally longer,which is unfavorable for liquid phase formation