Cadmium (Cd) is a common hazardous element that shows potential chronic toxicity in plants and animals. Arabis paniculata functioning as a hyperaccumulator has been found in the Yunnan–Guizhou plateau in China. This study characterizes the function of ApHIPP3 in A. paniculata to Cd stress, showing that the expression of ApHIPP3 was highly induced by Cd stress. Arabidopsis thaliana overexpressing ApHIPP3 showed stronger growth potential than wild type (WT). Cd accumulation capacity was significantly higher intransgenic A. thaliana than in WT. In addition, transgenic A. thaliana showed the ability to inhibit electrolyte leakage and eliminate reactive oxygen species (ROS). A strong interaction of ApHIPP3 with the clathrin heavy chain ApCHC1, which is known to play an important role in biotic and abiotic stresses, could be detected by a yeast two-hybrid assay. This was further confirmed by pull-down and co-immunoprecipitation (Co-IP) assays. Overall, these results demonstrate the function of ApHIPP3 to Cd stress and suggest a regulatory mechanism in response to Cd stress.