Research on the thermal behavior of light-burned magnesia entrained-flow calciner is one of the necessary basic works for optimizing thermal parameters and achieving energy saving and consumption reduction.Based on Euler-Lagrange theory,a numerical model of a company′s light-burned magnesia entrained-flow calciner was established.The basic laws of gas-solid flow,heat transfer and decomposition process in the calciner were studied,and the suitable calcination gas flow rate under the current production was determined.The results showed that the calcination flue gas in the main calciner rose in a swirling flow,and the center temperature was high as well as the wall was low.The swirling effect in the sub-calciner decreased sharply and the temperature tended to be uniform.Within the range of 4~18 m from the flue gas inlet,the gas-solid heat ex-change was intense and the materials were quickly decomposed up to 96%.Then the materials were completely decomposed at 24 m.The calcination gas flow rate was reduced to 91.22% of the original and the gas-to-material ratio was reduced to 1.46 Nm³/kg,which improved the space utilization rate of the calciner,and the fuel consumption per ton of product was reduced by 8.78%.