Provided are microelectrode array and method for preparing the same. The microelectrode array may have a modification layer disposed on a surface of an electrode thereof, and the modification layer comprises a platinum nanopillar modification layer, a platinum nanowire modification layer or a dendritic platinum modification layer. The modification layer can be adhered well to a substrate of the microelectrode and is less likely to fall off and cause electrode failure. The modified microelectrode has an increased surface area, reduced electrochemical impedance and increased charge injection capacity and charge storage capability of the electrode, this facilitating reducing the power consumption of an implantable system and improving the effect of electric stimulation.