The invention relates to a data terminal upgrading device and method. The device comprises a dialing module, a protocol module, a dynamic host configuration protocol (DHCP) server module, a router module, an IP processing module, an upgrading module and a web server module. The dialing module is used for completing dialing procedures, the upgrading module obtains private IP addresses from the DHCP server module, request message for detecting whether a new version exists or not is sent to a version server through the router module and the protocol module, and if the request message exists, the new version is downloaded from the version server, the new version is written into a flash of a data terminal, and the data terminal automatically starts up to complete upgrading. The data terminal upgrading device and method enables an upgrading process, a web server visiting process and a PC net playing process of the data terminal under a win8 operating system to be independent, reduces correlation between a data terminal upgrading process and a PC operation system, and further achieves a driving-free function through Microsoft win8 logo identification.