The present disclosure discloses a method and an apparatus for offloading Internet data in an access network, which are used for solving the technical problems that in a Network Address Translation (NAT) offloading networking solution, the information obtained in a monitor mode is incomplete, offloading characteristics for distinguishing users cannot be provided and offloading strategies are separated from Quality of Service (QoS) strategies of a core network. The solution of the present disclosure includes: an offloading device judges whether a Radio Access Bearer (RAB) data flow needs offloading according to a specific value of a specific parameter in an RAB message; if the offloading is needed, NAT is performed and then the offloaded data is transmitted to the Internet; and if the offloading is not needed, the RAB data flow is transparently transmitted to the core network. In the present disclosure, the offloading judgment condition, which the offloading device is in accordance with, directly originates from the core network, and the core network can proactively obtain required user information, thus offloading judgment can be made correctly and completely as much as possible, and offloading judgment can be implemented with QoS strategies of the core network together, and there is no need to add new QoS management points being independent of the core network.