The invention discloses a method and apparatus for improving the security of an LTE private network terminal. The method comprises the following steps: in an authentication process of a terminal to access a private network, acquiring a file key from a core network, and sending the file key to the terminal; after a file request sent by the terminal is received, encrypting a file specified by the file request by using the file key, and sending the encrypted file to the terminal; using the file key to decrypt the encrypted file by the terminal; and when the terminal is disconnected with the private network, deleting the file key from the local of the terminal. According to the method and apparatus disclosed by the invention, in an existing LTE connection process, a related step of acquiring the file key from the core network to encrypt the file, so that the terminal cannot access local files acquired from the private network when deviating from the private network environment, thereby improving the security of the private network terminal and avoiding the occurrence of file leakage.