Tea processing is an important factor affecting both the physicochemical composition and flavor quality of tea. The composition and content of amino acids in large-leaf yellow tea (LYT) during the manufacturing processes were determined by automatic amino acid analyzer, the dynamic changes of the measured amino acids during LYT processing were analyzed, and the principal component analysis (PCA) was applied for discrimination of the differences among various stages of tea processing. Results showed that a total of 22 amino acids were detected in tea samples, including 19 protein amino acids and three non-protein amino acids(theanine, β-alanine and γ-aminobutyric acid (GABA)). The compositions and contents of amino acids were quite different during LYT processes, and 22 amino acids could be detected in fresh tea leaves (FTL), fixing (Fx-LYT) and rolling (Ro-LYT) samples, while only 12 amino acids were identified in the finished tea (FF-LYT) that underwent high-temperature roasting. And the concentrations of these 12 amino acids in FF-LYT were significantly lower than those of FTL or re-yellowing (RY-LYT) samples. In the previous samples of FF-LYT with high-temperature roasting processing, theanine, aspartic acid, glutamic acid and glutamine were the most abundant amino acids, and the concentrations of the latter three were about 2.0 mg/g in these tea samples, whereas theanine concentrations were more than 9.40 mg/g in these samples, with the highest concentration was 13.43 mg/g observed in Ro-LYT. The contents of individual amino acid varied greatly during LYT processing, among which the variation coefficient (CV) of tryptophan was the largest (227.48%) and that of cysteine was the smallest (17.26%). In addition, to further distinguish the differences of LYT processes, the PCA analysis was performed on the detected amino acids. The tea samples, FTL, FF-LYT, Fx-LYT and re-roasting (RR-LYT) could be separated according to the processes, in particular, the distance between FTL and FF-LYT was far, indicating that heat treatment, especially for high-temperature roasting treatment affected the compositions and contents of amino acids in LYT. And the amino acids involved in the thermal reaction as aroma precursors or reaction substrates to produce volatile components, which was the probably reason for the reduction of their contents. The findings of this research can provide essential data support for the research on the formation of tea flavor quality in LYT, and offer a scientific theoretical basis for the processing, quality regulation and quality control of tea.