The invention discloses a porous silver catalyzer and process for preparing same, wherein the porous silver catalyzer has a dendritic porous structure, the sizes of bore diameters and pore walls range from 80 to 120 nanometers, the included silver atoms range from 88 to 93 percent, and the included gold atoms range from 7 to 12 percent. By adopting 'inverse dealloying' mode, the porous silver is prepared by using two steps as alloy material electrochemical corrosion and electrochemical reduction, the porous silver catalyzer and process for preparing same are simple in technology, convenient for operation and excellent in repeatability, moreover, the prepared catalyzer is non-supported, the bore diameters and the pore walls of the prepared porous silver are smaller, the specific surface areas are high, and the products can be easily recycled and reused.