The invention belongs to the technical field of K acid production, and particularly relates to a method for recovering R salt in K acid production mother liquor. The invention provides the method forrecovering R salt in the K acid production mother liquor. The method comprises the steps that a proper salting out reagent is selected and is cooperated with proper temperature control, so that the Rsalt can be quickly separated out from the K acid mother liquor, in addition, a temperature control process is favorable for crystallization and crystalline grain growth of the R salt in a separationout process, so that the R salt can be easily filtered and separated from the mother liquor through a simple solid-liquid separation way, and the technical problem that the R salt is difficult in separation and recovery by K acid mother liquor for a long time is solved.