The purpose of this study was to investigate the protein expression of egg white protein at different inlet temperatures of spray drying (140,160,180 ℃). ITRAQ technology was used to identify and bioinformatics egg white proteins, and to investigate the distribution, function and mechanism of different proteins in egg white powder during different drying processes. The results showed that, compared with the control group at 140 ℃, 41 and 46 different proteins were identified at 160 ℃ and 180 ℃ respectively during the spray drying process of egg white (Fold change ＞1.2, P＜0.05). GO function annotation analyzed the biological processes that the differential proteins of different drying inlet temperatures mainly participate in were cellular processes, biological regulation and binding. KEGG enrichment analysis showed that 6 significantly changed proteins were classified as metabolic pathways, and the significantly changed differential proteins were enriched in the lysosomal pathway. In addition, among the different proteins, four proteins were screened to show significant changes in abundance during the spray drying process, namely, ovalbumin associated protein Y, ovalbumin precursor, ovalmucin subtype X2 and ovalbumin subtype 1 precursor. This study provides references for the processing methods and biological functions of egg white processed by spray drying.