Abstract: Patients with phenylketonuria (PKU) have to restrict the intake of phenylalanine (Phe) or its structural analogues for life because of the genetic defect that prevents them from metabolizing Phe normally. Therefore, the research and development of food for special medical purpose for PKU is important to protect the health of patients and improve their quality of life. This paper reviews the dietary regimen for patients with PKU, focusing on special low-protein foods, low-Phe foods, and food for special medical purpose based on glycomacropeptides, and details the sources or preparation techniques and functional properties of these foods, and look into future research directions and research priorities to address the current problems of single product form and poor palatability in this field, with a view to providing a better understanding of the development of food for special medical purpose for PKU. The research direction and focus of future research are also presented to provide reference for the research and development of food for special medical purpose for PKU.