The refinement of solidificationSolidification structure has a direct influence on improving the mechanical propertiesMechanical properties of AH36 high-strengthStrength ship plate steelSteel and preventing the formation and propagation of cracksCrack during solidificationSolidification. In this study, the effect of Ce content on the solidificationSolidification structure of AH36 steelAH36 steel ingot is investigated through a Cellular Automata-Finite Element (CAFE) solidificationSolidification microstructureMicrostructure prediction modelPrediction model, validated by laboratory vacuum induction melting and casting experiments. Numerical simulationNumerical simulation reveals that increasing Ce content increases the equiaxed grain ratio significantly, gets higher grain densityDensity and a notable reductionReduction in average grain sizeAverage grain size. Experimental results confirm the numerical predictions, demonstrating that the addition of 53 ppm Ce increases the equiaxed crystal ratioEquiaxed crystal ratio from 6.45 to 12.73% while reduces the average grain sizeAverage grain size from 1526.68 to 927.21 μm. Further increasing the Ce content to 89 ppm enhances the equiaxed crystal ratioEquiaxed crystal ratio to 17.57% and decreases the average grain sizeAverage grain size to 529.79 μm, resulting in a pronounced refinement of the prior austenite grains. These findings indicate that the rational selection and addition of rare earthRare earth elements can effectively refine the solidificationSolidification structure, enhance the hot ductility of the steelSteel, and thereby reduce the risk of crackCrack formation during production.