A method for preparing a flexible electrode is provided. The method comprises sequentially forming a flexible base layer and an intermediate conductive layer on a carrier plate; treating an elastomeric template having an electrode pattern with an acid, followed by transferring and printing the electrode pattern onto the intermediate conductive layer to form an electrode inducing layer; forming a titanium dioxide-polydopamine composite layer in a gap of the electrode inducing layer; forming a platinum electrode layer on the titanium dioxide-polydopamine composite layer; removing the carrier plate. The invention solves the problems of slow formation of a polydopamine film and slow formation of a platinum electrode layer. A flexible electrode is further provided.