The invention discloses an Ag-doped beta-Co(OH)2 super capacitor electrode material. A preparation method of the material is relatively low in cost and simple in process; through doping noble metal Ag, the conductivity of the material is greatly improved; the obtained product is uniform in size and single in form and shape; the diameter of the product is about 2 microns; generation of cracks on the surface of a compound is beneficial to diffusion of an electrolyte, so that the specific capacitance of the material is improved; and meanwhile, the product has a relatively large specific surface area and has good electrochemical properties when used as the electrode material. An Ag-doped beta-Co(OH)2 microflower is applied to a super capacitor as the electrode material and can have good stability and an excellent electric capacity.