Abstract: This study investigated the effects of different processing techniques on the flavor compounds of ancient tree white tea using summer-autumn fresh leaves harvested from ancient tea trees in Tangba Town, Yanhe County, Guizhou Province. Four processing protocols were designed and implemented: A (compound withering→sun-drying); B (compound withering→sun-drying followed by baking); C (natural withering→sun-drying); D (natural withering→sun-drying followed by baking). A commercially available creamy white tea served as the control (CK). The influence of processing on key flavor substances was systematically analyzed by determining primary taste components, catechin profiles, organic acids, and volatile aroma compounds. Methods including principal component analysis (PCA), cluster analysis, and odor activity value (OAV) calculation were employed to elucidate the regulatory mechanism of processing on flavor formation. The results indicated that processing techniques significantly affected the taste and aroma profiles of the ancient tree white tea. Tea samples produced by process C (natural withering combined with sun-drying) exhibited significantly higher contents of free amino acids (3.13%), soluble sugars (82.01 mg/g), and caffeine (4.38%), while having lower levels of total tea polyphenols, total catechins, and total organic acids. This composition suggested a flavor profile characterized by pronounced umami and sweetness with effectively suppressed bitterness, astringency, and sourness. Aroma analysis identified 74 volatile compounds, with linalool showing the highest OAV across all samples. Thirty-five key aroma components were screened based on OAV, among which ethyl acetate, 2-methylbutanal, myrcene, n-hexanal, 2-pentylfuran, and linalool contributed significantly to the overall aroma. The aroma composition of process C was relatively similar to that of CK. However, the ancient tree white tea still contained lower levels of key creamy aroma compounds, such as 2-pentylfuran, compared to CK, indicating potential for enhancing the creamy note by optimizing leaf maturity and drying temperature. In conclusion, the process combining natural withering with sun-drying (C) was most favorable for enhancing the umami-sweet taste and optimizing the aroma composition of ancient tree white tea, providing a theoretical basis for its refined processing and targeted flavor modulation.