A method and device for transmitting Internet Protocol (IP) data packet are disclosed by the present invention, the method comprising: an Access Point (AP) device obtains an IP data packet needing to be sent to an User Equipment (UE); said AP device use the type information of said IP data packet to determine the corresponding Data Radio Bearer (DBR) of said IP data packet; Said AP device sends said IP data packet to said UE through said DBR; in the embodiments of the present invention, when the AP device accesses the IP network locally or directly through the IP network, the Quality of Service (QoS) insurance of IP data packet in the air interface transmission is implemented, on the basis of the direct mapping between the type information and the data radio bearer.