Method and device of data transmission

The invention discloses a method and a device of data transmission. The method comprises that data from a user device are received through a gateway device; an address filtering list which is maintained in advance is inquired by the gateway device according to a destination address of the data, a flow type of the data is obtained, and the address filtering list is used for recording the corresponding relation between the address and the flow type; and a target public data network (PDN) is confirmed by the gateway device according to the flow type of the data, and corresponding process is conducted on the data or the data are sent to the target PDN. According to the method and the device of the data transmission, split-flow treatment is conducted on the data by the gateway device, data processed by a comprehensive gateway are sent to the comprehensive gateway, and therefore the data processing pressure of the comprehensive gateway can be reduced.