Embodiments of the present invention provide a method and a device for establishing a packet data network PDN connection. A method includes: receiving, by a trusted wireless local area network access network TWAN device, a trigger message from a user equipment; obtaining, by the TWAN device, an access point name APN from the user equipment; sending, by the TWAN device, a create session request message carrying the APN to a PDN gateway; receiving, by the TWAN device, a create session response message carrying an IP address from the PDN gateway; and sending, by the TWAN device, the IP address to the user equipment. In this way, an additional PDN connection or a non-default PDN connection is established for a user equipment to extend a network access range of the user equipment.