Disclosed are a method and terminal for accessing a network and acquiring client identification module information and a core network. The terminal transmits an attach request to an Internet of Things core network, where the attach request carries a device identifier of the terminal and a subscriber identification module (SIM)-free access indication, thus allowing the Internet of Things core network to allow, on the basis of the SIM-free access indication, attachment of the terminal and to assign a temporary identifier to the terminal; the terminal receives an attach response transmitted by the Internet of Things core network; the terminal transmits a packet data protocol (PDP) context activation request to the Internet of Things core network, thus allowing the Internet of Things core network to accept the PDP context activation request and to assign a dedicated internet protocol (IP) address to the terminal; the terminal receives an activation successful message transmitted by the Internet of Things core network, where the activation successful message carries the dedicated IP address; and the terminal receives the server address list transmitted by the Internet of Things core network.