Abstract: The present invention relates to a double metal cyanide catalyst comprising a polyether compound, a metal salt, a metal cyanide salt, and an organic complexing agent having an acetate group or a tartrate group; a preparation method therefor; and a method for preparing a polycarbonate polyether polyol by copolymerizing carbon dioxide and an epoxy compound in the presence of the catalyst. According to the present invention, the double metal cyanide catalyst has excellent in catalytic activity and has a short catalytic activity induction time, according to an embodiment of the present invention, the process for preparing the catalyst of the present invention is eco-friendly and simple in process, since an amount of the organic complexing agent to be used is small, and has a simple process.