The invention discloses a process for separation of acid and salt in salt-containing waste acid. The process includes: subjecting salt-containing waste acid to multi-period adsorption-elution treatment by an acid adsorption resin column, during adsorption, passing waste acid return liquid, residual waste acid liquid and a salt-containing waste acid stock solution obtained in a previous period sequentially through acid adsorption resin from the bottom up for acid adsorption, collecting residual elution water, deacidified salt-containing liquid and waste acid return liquid successively, stoppingliquid feeding after the volume meeting the requirement, completely feeding salt-containing waste acid in the first period, during elution, passing elution water return liquid, residual elution waterand elution water obtained in a previous period through acid adsorption resin from top to bottom in sequence for elution, and collecting residual waste acid liquid, desalted acid-containing liquid and elution water return liquid successively, stopping water inflow after the volume meets the requirement, completely feeding elution water in the first period, and performing repetition till completing treatment of the salt-containing waste acid. The process disclosed by the invention can be used for separation of various acids and cations, has good separation effect, is not limited by the heightof the resin column, does not generate volume expansion, and has wide applicability.