The invention provides a managing method of a shared key, which is used for realizing preservation and use of the shared key in a terminal of a communication system, which comprises the following steps: step 602, distributing the shared key when a user adds a network, adopting a public cryptography of an initial user to encrypt the shared key, and writing the encrypted shared key into a nonvolatile memory of a PC card through an interface of the PC card; step 604, inputting a username and a public password of the initial user in a dialing software interface when the user starts the terminal for the first time to log on the network; and step 606, decrypting the encrypted shared key which is read by the interface with the dialing software to obtain the shared key, and utilizing the structureof the shared key to extend a judge right protocol message so as to pass the judge right. Therefore, the invention facilitates net-surfing convenience of the user, ensures the use safety of the shared key and at the same time allows a plurality of users to go online with one same PC card.