The invention provides a mobile communication network system supporting a virtual SIM card and the authentication method thereof. Based on a current mobile communication network system, function modules are arranged on a mobile terminal, an authentication center and a call center service system; a password card is introduced to support the registration, the authentication, the network use and theexpense computation of a virtual SMI card; programs and functions realized by the real SIM card are realized by the mobile terminal; account information is written into the mobile terminal through a mobile communication network by the local retrofit and the program updating to mobile network equipment, and an account is not activated by selling the real SIM card. The invention realizes the reduction of roaming fees and the reduction of the consumption of the SIM card in the transnational or trans-provincial or trans-municipal application, thereby reducing the waste of the resource. The invention provides a convenient, flexible, safe mode of using mobile phones in different places. To adopt the mobile communication network system supporting the virtual SIM card contributes to the realization of new functions of the mobile terminal and the decrease of the cost, and ensures that the popularization of the new functions gets easier.