Non-thermal processing technology has been widely used in the food processing industry. Dense phase carbon dioxide (DPCD), an emerging non-thermal processing technology, has become the focus of food processing technology researchers worldwide due to its low energy consumption, non-toxicity and harmlessness, and small impact on food quality. As an important component of food, protein directly affects the flavor, texture and nutrition of food. An overview of DPCD processing technology is presented in this article. Moreover, it summarizes the current state of the art in understanding the effect of DPCD on protein structure and processing characteristics, and discusses future prospects for this processing technology. Hopefully, this review will provide new ideas for researchers working on the application of non-thermal processing technologies in food processing.