Improved network connecting device

The utility model relates to an improved network connection device that utilizes the original functions of a subscriber identity module card such as the function of security realized by providing authentication and encryption. Therefore, the utility model deploys the subscriber identity module card in the network connection device such as a router in order to prevent the information form being stolen or disclosed. The subscriber identity module card can also be set as an element to start the network connection device, thereby enhancing the security when the information is transformed on the Internet. If the network connection device is provided with software with encryption function, the software and the subscriber identity module card form a double protection, and the subscriber identity module card is an SIM card.