A UPLC method was established to create fingerprint profiles for 12 batches of lavender samples. The antioxidant capacity of lavender was evaluated using three methods:DPPH radical scavenging assay, ABTS radical scavenging assay, and reducing power assay. Gray relational analysis was employed to explore the "spectrum-effect" relationship of lavender. The results indicated that the UPLC fingerprint profiles of the 12 batches exhibited similarity indices ranging from 0.932 to 0.996. A total of 26 common peaks were identified, and among these, 5 compounds were successfully identified using reference standards, with their respective contents being quantified. The in vitro antioxidant assays demonstrated varying degrees of antioxidant activity across all 12 lavender samples. The samples exhibited consistent DPPH and ABTS radical scavenging abilities; specifically, sample S3 showed the weakest scavenging capability, while sample S12 exhibited the strongest. In the reducing power assay, samples S11 and S12 demonstrated the weakest and strongest reducing effects, respectively. This study provides scientific evidence and data support for the comprehensive research on the antioxidant properties of lavender.