AP2/ERF transcription factor family members have been identified to play important roles in abiotic stress responses. In this study, the full-length coding sequence of the FtDREB6 gene was cloned with a length of 615 bp, which encodes for 204 amino acids residues, with a molecular weight of 22.7 kDa and an isoelectric point of 4.96 from tartary buckwheat (Fagopyrum tataricum) cultivar “Pinku 1”. The sequence of FtDREB6 represented higher homology with Arabidopsis thaliana AtERF043 by the sequence alignment on TAIR website. FtDREB6 gene was showed without the transcription activity by transactivation analysis. Moreover, by transforming the coding sequence of FtDREB6 into A. thaliana by Agrobacterium-mediated transformation approach, transgenic FtDREB6-overexpressing plants showed significant increase on the drought resistance. The expression vector containing FtDREB6 gene was transformed into Agrobacterium rhizogenes A4, which was subjected to infect explant for inducing the hairy roots. Under D-Mannitol treatment, the superoxide dismutase activity and catalase activity in overexpressing hairy roots were significantly higher than that of the control, and the content of malondialdehyde was significantly lower than the control. These results indicated that FtDREB6 was involved in responses to drought stress, which provided a reference for future deciphering the molecular mechanism for drought tolerance in tartary buckwheat.