A method for Internet access of a data card, comprising: after a data card is connected to a host, receiving, by the data card, a USB command sent by a USB host driver of the host; determining, by the data card according to the USB command, whether a current operating system run on the host is the Windows operation system; if the current operation system run on the host is the Windows operation system, the data card reports a device descriptor that is compliant with a requirement of a device specification of a remote network device interface specification, RNDIS, protocol to the host; if the current operation system run on the host is not the Windows operation system, the data card reports a device descriptor that is compliant with a requirement of a device specification of an Ethernet control model, ECM, protocol to the host; receiving, by the data card, an initialization command that is compliant with an Ethernet interface protocol sent by the USB host driver of the host; performing, by the data card, a corresponding initialization operation according to the received initialization command, and mapping the data card into an Internet access device by using the Ethernet interface protocol; obtaining, by the data card, dial-up information and dialing by using the dial-up information to request to connect to a network; and performing, by the Internet access device, communication between the host and the network; the obtaining, by the data card, dial-up information and dialing by using the dial-up information to request to connect to a network comprises: when pre-stored dial-up information exists, obtaining the pre-stored dial-up information, and dialing by using the pre-stored dial-up information to request to connect to the network, wherein the pre-stored dial-up information is one piece of the following dial-up information: previous dial-up information of a user, dial-up information of an operator, and dial-up information stored in a subscriber identity module card inserted in the data card; when no pre-stored dial-up information exists, obtaining dial-up information entered by a user on a Web page, and dialing by using the dial-up information entered by the user to request to connect to the network; wherein for a wideband code division multiple access network, dial-up information comprises a dialing number and an access point name identifier string. after a data card is connected to a host, receiving, by the data card, a USB command sent by a USB host driver of the host; determining, by the data card according to the USB command, whether a current operating system run on the host is the Windows operation system; if the current operation system run on the host is the Windows operation system, the data card reports a device descriptor that is compliant with a requirement of a device specification of a remote network device interface specification, RNDIS, protocol to the host; if the current operation system run on the host is not the Windows operation system, the data card reports a device descriptor that is compliant with a requirement of a device specification of an Ethernet control model, ECM, protocol to the host; receiving, by the data card, an initialization command that is compliant with an Ethernet interface protocol sent by the USB host driver of the host; performing, by the data card, a corresponding initialization operation according to the received initialization command, and mapping the data card into an Internet access device by using the Ethernet interface protocol; obtaining, by the data card, dial-up information and dialing by using the dial-up information to request to connect to a network; and performing, by the Internet access device, communication between the host and the network; the obtaining, by the data card, dial-up information and dialing by using the dial-up information to request to connect to a network comprises: when pre-stored dial-up information exists, obtaining the pre-stored dial-up information, and dialing by using the pre-stored dial-up information to request to connect to the network, wherein the pre-stored dial-up information is one piece of the following dial-up information: previous dial-up information of a user, dial-up information of an operator, and dial-up information stored in a subscriber identity module card inserted in the data card; when no pre-stored dial-up information exists, obtaining dial-up information entered by a user on a Web page, and dialing by using the dial-up information entered by the user to request to connect to the network; wherein for a wideband code division multiple access network, dial-up information comprises a dialing number and an access point name identifier string. when pre-stored dial-up information exists, obtaining the pre-stored dial-up information, and dialing by using the pre-stored dial-up information to request to connect to the network, wherein the pre-stored dial-up information is one piece of the following dial-up information: previous dial-up information of a user, dial-up information of an operator, and dial-up information stored in a subscriber identity module card inserted in the data card; when no pre-stored dial-up information exists, obtaining dial-up information entered by a user on a Web page, and dialing by using the dial-up information entered by the user to request to connect to the network; wherein for a wideband code division multiple access network, dial-up information comprises a dialing number and an access point name identifier string.