The present research aimed to explore the influence of different felt-proofing methods on alpaca fibers’ scale structure. Dyed alpaca fibers were exposed to a particular wavelength of ultraviolet (UV) light for different periods and treated with protease to analyze the felt property and compare with untreated fibers. Experimental results have shown that alpaca fibers have better shrinkage resistance and dyeability after being exposed to UV light, whereas no recognizable change was obtained on the surface of alpaca fibers’ scale structure by scanning electron microscopy (SEM). In contrary, enzyme-treated alpaca fibers revealed improved dye rate and resistance to shrinkage. Especially, damaged scales on many areas of fiber surface were appeared by SEM, which indicates that UV may have a positive effect on enzyme treatment by damaging alpaca fibers’ surface structure and promoting the amount of protease going into the fibers’ inner layers. Therefore, eventually a better shrinkage resistance was obtained.