The lipoxygenase–hydroperoxide lyase (LOX-HPL) pathway is responsible for the biosynthesis of green leaf volatiles and traumatic acid (TA) in plants; however, the feedback regulatory role of TA in tea plant remains poorly understood. Here, we applied a gradient of exogenous TA concentrations (10⁻⁸–10⁻⁴ M) to both pre- and post-harvest tea leaves, and systematically determined fatty acid precursors, key enzyme activities, and structural gene genes in the LOX-HPL pathway. Moderate TA treatment (10⁻⁷ M) markedly enhanced the activities of LOX and ADH in post-harvest leaves, while concurrently upregulating multiple upstream CsLOX genes. Higher TA concentrations suppressed both enzyme activities and gene transcription. In pre-harvest leaves, the optimal concentration shifted to 10⁻⁶ M for gene upregulation. Higher TA concentrations (≥10⁻⁶ M post-harvest, ≥10⁻⁵ M pre-harvest) consistently suppressed both enzyme activities and gene transcription. Optimal TA treatment also markedly reduced ALA accumulation, indicating feedback inhibition on precursor pools. TA mediates feedback regulation of the LOX-HPL pathway, with its regulatory effect influenced by TA concentration and tissue type, providing a potential strategy for modulating fatty acid-derived flavor quality in tea production.