Method for purifying rhodium-diphosphite catalyst

The invention discloses a method for purifying a rhodium-diphosphite catalyst, belonging to the field of petrochemical industry. The method comprises the following step: carrying out counter-current extraction and washing on a rhodium-diphosphite catalyst solution by using an extracting tower for realizing purification, wherein the extracting tower comprises an extraction section, a first settling section and a second settling section, the first settling section is connected with the top of the extraction section, and the second settling section is connected with the bottom of the extraction section. The method provided by the invention can be used for removing acidic materials produced by the decomposition of catalyst ligand in the rhodium-diphosphite catalyst solution, and is especially used for removing the acidic materials produced by the decomposition of the catalyst ligand after hydroformylation is finished and trace heavy component byproducts contained in the catalyst; the method can effectively reduce