The invention discloses a preparation method for regenerating rear-earth polishing powder. The preparation method comprises the following processes: (1) mixing the waste rear-earth polishing powder and adopting a shaker reselecting device for reselecting and separating to obtain heavy constituents; (2) treating the reselected rear-earth polishing powder by 2%-25% (in percentage by weight) of ammonium fluozirconate aqueous solution; heating up to 50 DEG C to 75 DEG C; stirring and reacting for 6-12 hours; and settling, cleaning and filtering to recycle solid; and (3) preparing regenerated rear-earth polishing powder, wherein the primarily generated rear-earth polishing powder is primarily dried, roasted for 3-10 hours at 1000 DEG C to 1100 DEG C, cooled, crushed by gas flow to obtain the regenerated rear-earth polishing powder which can reach a grain size range for being reused as the polishing powder. The preparation method for regenerating rear-earth polishing powder has the advantages of being less in using amount of chemical substances, simple in process, easy to control conditions, low in production cost, easy to realize industrial production, high in recovery rate, good in powder polishing effect and the like.