Abstract: Biodegradable and biocompatible functional polymers show high potential as novel drug carriers in disease diagnosis and therapy. Recently, protein drugs have brought about major breakthroughs in the treatment of various diseases including cancer, while the development of carrier technology is relatively delayed. This article reviews recent advances in biodegradable functional polymers as protein drug nanocarriers. Additionally, we have discussed the perspective of developing new generations of biocompatible and functional polymers.