The paper reviews the current research situation of FPE (format-preserving encryption) including basic constructing methods, encryption modes and security. When describing the basic constructing methods, it introduces the basic principles of Prefix, Cycle-Walking and Generalized-Feistel and their application scopes. When explaining the encryption modes, it mainly analyzes the construction features of FPE modes or schemes, introduces the principles of three classical modes, summarizes the different types of Feistel networks and presents an overview of their applications in FPE. When talking about the security, it describes the security notions of FPE and their corresponding games, analyzing the relationship among them. In the end, it introduces the application scopes of FPE and points out that performance, integrity authentication and key problems of database encryption with FPE, such as making range query and arithmetic operation on encrypted data, are the major problems to be solved in the future. All these works will play a role in promoting research of format-preserving encryption.