It discloses a novel process for refining cefamandole nafate, comprising: 1) adsorbing cefamandole nafate with strongly acidic ion exchange resin, followed by eluting the resin and collecting the eluate, to provide a primary purified cefamandole acid after concentration under reduced pressure 2) neutralizing the primary purified cefamandole acid with an aqueous solution of sodium hydroxide or an aqueous solution of basic salt of sodium, followed by adjusting the pH value and filtrating out the insoluble substances with heating, thereby providing a secondary purified aqueous solution of cefamandole nafate and 3) adding ethanol in a volume ratio between ethanol and water of 4:6 into the aqueous solution, to allow recrystallization under controlling the temperature, to provide a tertiary purified cefamandole nafate. The refined cefamandole nafate product has a purity of no less than 99.5%, mostly no less than 99.6%, with significantly low content of heavy metals.