usim card means an upgraded version of ordinary SIM card. USIM is the abbreviation of "UniversalSubscriberIdentityModule" (Global Subscriber Identity Card). In the field of mobile communication systems, USIM is also called the Universal Subscriber Identity Module. USIM is one of the components of the mobile communication system and an integral part of the user terminal equipment. USIM card is an upgrade of SIM card and is the third generation mobile communication phone card. Unlike the SIM card, the USIM card does not only have a simple authentication function. It is gradually transitioning to a mobile commerce platform and eventually a multi-application platform. It is no longer difficult to implement other applications such as electronic wallets, electronic credit cards, and electronic bills on mobile phones. This feature makes the USIM card a medium for cross-field cooperation and mutual penetration of operations in different industries. In addition to supporting multiple applications, the USIM card has also upgraded its security algorithm and added the card's network authentication function. This two-way authentication can effectively prevent hackers from attacking the card. At the same time, the phone book function of the USIM card is more powerful. Not only does the number of stored phone numbers increase, but each phone user can also choose whether to record other information, such as email, aliases, other numbers, etc.