Mechanical wounding is a common factor inducing herbivore-induced plant volatiles (HIPVs) production during almost all insect infestations. Additionally, α-farnesene is one of the HIPVs that accumulate in tea plants following infestations by most insects. However, the specific mechanism underlying the wounding-regulated accumulation of α-farnesene remains unclear, especially at the level of epigenetic regulation. Moreover, α-farnesene in tea plants has not been functionally characterized. In this study, we observed that histone deacetylase inhibitors treatment can induce the accumulation of α-farnesene. Subsequent analyses of protein interactions and GUS activity revealed that the histone deacetylase CsHDA6 can interact directly with CsMYC2, which is an important transcription factor in the jasmonic acid (JA) pathway, and co-regulate the expression of the key α-farnesene synthesis gene CsAFS. Wounding caused by an insect infestation affected CsHDA6 production at the transcript and protein levels, while also inhibiting the binding of CsHDA6 to the CsAFS promoter. The resulting increased acetylation of histones H3 and H4 in CsAFS enhanced the expression of CsAFS and the accumulation of α-farnesene. Furthermore, a large amount of α-farnesene can protect tea plants from tea geometrid infestations by attracting the natural enemy of the insect pest. In conclusion, our study demonstrated the effect of histone acetylation on the production of tea plant HIPVs and revealed the importance of the CsHDA6-CsMYC2 transcriptional regulatory module for the accumulation of the anti-insect metabolite α-farnesene in tea plants following an insect infestation.