This study investigated the effect of different concentrations of cerium sulfate Ce₂(SO₄)₃ on the grain refinement of nickel deposition layers during the electrochemical deposition process in industrial electrolytes. The impact of different Ce₂(SO₄)₃ concentrations on nickel electrodeposition behavior was analyzed using the linear sweep voltammetry (LSV) curve, cyclic voltammetry (CV) curve and chronoamperometry (CA) curve. The microstructure morphology and grain size of the deposition layers were analyzed using scanning electron microscopy and the preferred orientation and crystal structure were analyzed using X-ray diffraction. The results show that the addition of different concentrations of Ce₂(SO₄)₃ to the industrial electrolyte leads to a negative shift in the starting deposition potential of nickel, an increase in cathode polarization degree, an increase in overpotential, a shortened nucleation relaxation time t_m and an accelerated nucleation rate during nickel electrodeposition, resulting in grain refinement of the deposition layers. However, the addition of Ce₂(SO₄)₃ does not modify the nucleation mechanism of nickel electrocrystallization, nor does it change the crystal structure of the nickel deposition layer, which still remains a face-centered cubic (fcc) structure. When 0.6 g/L Ce₂(SO₄)₃ is added, the grain growth orientation is transformed from the (111) plane to a bidirectional preferred growth of the (111) and (220) planes. At this point, the grain distribution in the deposition layer is uniform, and the grains undergo obvious refinement.