A communication method for a host and a wireless Internet access module, and a data card, are provided so that the host implements wireless Internet access with the wireless Internet access module of a secure digital interface. The method includes simulating each port on a wireless Internet access processing function unit in a wireless Internet access module into a secure digital card partition and reporting the secure digital card partition to a host side; receiving downlink interaction information from the host side encapsulated in a secure digital card interface format, decapsulating the downlink interaction information, and delivering the decapsulated downlink interaction information to a corresponding port; and receiving uplink interaction information reported to the host side from each port, and encapsulating the received uplink interaction information in the secure digital card interface format.