The invention discloses a method for adding a special function number for users, which comprises: one or more minor numbers and dial modes corresponding to individual minor number are set for a user; when the user originates a call, the system sends the number corresponding to the dial mode to a called party; when other users calls the minor number of the user, the system performs the authentication of the calling party; after the authentication is passed, the system continues based on a major number corresponding to the minor number and adds an access code before the calling number. The invention also discloses a system for adding the special function number for users, which comprises a mobile phone network and/or fixed-line phone network, a mobile terminal and/or a fixed-line terminal, and a 'single SIM multiple number' service platform, a databank and an authentication server which are equipped in the network and connected with one another. The invention can display different calling numbers in the called party when the user is the calling party and perform the caller authentication of the calling minor numbers, so that the invention ensures the use safety of the user's number and avoid the malicious dissemination.