Recently, much attention has been paid to two-dimensional MOF nanosheets (MONs) due to their widespread application in many specific areas. In this work, a simple and efficient congenerous-exfoliation strategy was developed to prepare vast and uniform few-layered Ni2+@Ce-MOF (Ce-MOF: {[Ce(HPIA)(PIA)(H2O)2]·H2O}n) nanosheets with a thickness of ca. 10 nm. In the exfoliation process, the synergistic action of Ni2+ and methanol solvents under ultrasonication plays a major role in restraining the interactions between the layers. Importantly, supercapacitor applications indicate that the exfoliated Ni2+@Ce-MOF nanosheet shows a remarkable improvement in the specific capacitance (921.05%) in comparison with that of the bulk Ce-MOF sample before modification.