Animal glue and egg white are important proteinaceous binding media of ancient polychromy artworks, and the research of their structural changes caused by light aging is highly related to the exploration of pathological changes mechanism as well as the selection of scientific materials and proper conservative methods. Regarding the animal glues (bone, rabbit skin, sturgeon) and egg white in Kunsthistorisches Museum Vienna as the study objects, this paper aimed at studying the protein secondary structure changes after light aging by Fourier transform infrared spectroscopy (FTIR) with the help of deconvolved Amide I and Gaussian fitting method. Results illustrated that the four binders still possessed the typical FTIR spectra characteristics after light aging in spite of some peaks shift, among which glycosidic bond in egg white showed an obvious blue shift. Moreover, deconvolved Amide I and Gaussian fitting results indicated that the contents of α-helix, parallel β-sheets, anti-parallel β-sheets, β-turns and random coils of each binder varied after the light aging. To be specific, α-helix’s content of the bone decreased 22.24% but random coils increased 9.76%, which deduced the uncoiling of the α-helix caused by light. The α-helix’s contents of the rabbit skin and sturgeon reduced 5.31% and 4. 15% respectively, and random coils content of the former showed the minimum growth (6.96%) while that of the latter decreased. Thus, these two were supposed to be of high stability versus light. Egg white showed the poorest light stability due to the highest reduction of α-helix (44.45%) and obvious rise of random coils (27.49%). In addition, the anti-parallel β-sheets’ contents of all the binders increased while the β-turns kept stable. Parallel β-sheets showed a decline trend among all the binders except the sturgeon glue. This research confirmed the feasibility of studying the proteinaceous binders’ secondary structure changes by deconvolved Amide I, Gaussian fitting method and FTIR spectroscopy, which was proved to be a promising method in studying the aging phenomenon of the proteinaceous binders in artworks. However, the transformation mechanism needs further explorations.