The enantiomerically pure (S)-N,N-dimethyl-1-ferrocenylethylamine was racemized by a free radical process, with the catalyst of thiol and the initiator of azodiisobutyronitrile (AIBN). The effect of reaction conditions on racemization was optimized by experiments. The results showed that (S)-N,N-dimethyl-1-ferrocenylethylamine could be completely racemized under the following reaction conditions: the molar ratio of (S)-N,N-dimethyl-1-ferrocenylethylamine to thiol and AIBN was 1:1.2:0.6, AIBN was added dropwise in 18 h, and the reaction mixture was refluxed in toluene. Besides, the catalyst of a novel crosslinked mercaptopolystyrene resin was synthetized, and the e.e.% of the racemate could be reduced to 12% with tentative research on the catalytic effect.