The invention discloses a catalyst preparation kettle used for preparing a carbon dioxide-epoxypropane copolymer, which comprises a cylindrical kettle body, the kettle body is vertically arranged, a center rotating shaft connected to an external first motor is vertically arranged in the kettle body, a stirrer is arranged on the center rotating shaft, the stirrer comprises a U-shaped stirring frame and a stirring blade positioned in the U-shaped stirring frame, an eccentric rotating shaft which is connected to an external second motor and is parallel to the center rotating shaft is arranged in the kettle body, an emulgator is arranged at the lower end of the eccentric rotating shaft, the emulgator is positioned between the U-shaped stirring frame and the stirring blade, the stirring blade comprises two sheets of flat and straight blades which are interlaced and arranged on the center rotating shaft and two sheets of vertical straight blades which are respectively fixed and arranged at the free ends of the flat and straight blades, the catalyst preparation kettle has the advantages that under dual-function condition of stirring and emulsification, various catalysts are fully fixed and emulsified, catalyst effect can be performed with max limitation, so that the reaction efficiency and product yield can be increased.