Slag glass-ceramics doped with different proportions of CeO2 were prepared by fusion casting method using iron tailings andfly ash as raw materials. The effect of CeO2 on the activation energy and crystallization pattern of glass-ceramics under theeffect of ohmic thermal radiation and microwave radiation was investigated. The experimental results show that thecrystallization activation energy of glass-ceramics gradually increases with the addition of CeO2, and the diopside crystallizationis suppressed. Compared with conventional heat-treated samples, microwave irradiation effectively reduces the glass transitiontemperature, mainly depending on the enhanced crystallization kinetics by microwave non-thermal effects. Further analyzedby Raman spectroscopy, the microwave effect promoted the combination of Ce4+ with [SiO4] to generate fully depolymerizedQ0, inhibited the generation of Q2 and Q3, and increased the glass stability.