以MnO、ZnO和Fe₂O₃为基础原料，固定其配比后，添加质量分数在0~1.0%的CaO，采用传统两步合成工艺制备Mn-Zn铁氧体，研究CaO对铁氧体微观结构和磁性能的影响。结果表明：随着CaO添加量的增加，Mn-Zn铁氧体的平均晶粒尺寸和烧结密度先增大后减小，2.2 MHz频率下的弹性磁导率先增大后急剧减小再略微增大，1 T磁场强度下的饱和磁化强度先增大后减小，矫顽力先减小后增大；适量CaO可以改善Mn-Zn铁氧体的微观结构，降低铁心损耗；当CaO质量分数为0.4%时，Mn-Zn铁氧体在1 T磁场强度下的饱和磁化强度最大，为46 A·m²·kg^-1，2.2 MHz频率下的弹性磁导率较大，为86.7，损耗功率较低，约为20 kW·m^-3，矫顽力较低，约为183.4 kA·m^-1，Mn-Zn铁氧体的综合磁性能较好。

After fixing the ratio of basic raw materials of MnO, ZnO and Fe₂O₃, and then adding CaO with mass fractions of 0-1.0%, the Mn-Zn ferrite was prepared by traditional two-step synthesis process. The effect of CaO on microstructure and magnetic properties of Mn-Zn ferrite was studied. The results show that with increasing CaO addition content, the average grain size and sintering density of Mn-Zn ferrite increased first and then decreased; the elastic permeability at the frequency of 2.2 MHz increased first, then sharply decreased, and then slightly increased; the saturation magnetization at the magnetic field intensity of 1 T increased first and then decreased; the coercivity decreased first and then increased. Adding proper amount of CaO could improve microstructure of Mn-Zn ferrite and decrease core loss. When the content of CaO was 0.4wt%, the Mn-Zn ferrite had the largest saturation magnetization at the magnetic field intensity of 1T of 46 A·m²·kg^-1, the relatively large elastic permeability at the frequency of 2.2 MHz of 86.7, the relatively low loss power of about 20 kW·m^-3 and the relatively low coercivity of 183.4 kA·m^-1, and the Mn-Zn ferrite had the good comprehensive magnetic properties.