Provided is a method, network device and system for implementing data processing. The method includes: transmitting, by a first network device, a request message to a second network device; feeding, by the second network device, a response message back to the first network device according to the request message received from the first network device; receiving, by the first network device, the response message fed back by the second network device, and transmitting an indication message to a third network device; and receiving, by the third network device, the indication message transmitted by the first network device, and processing data according to the indication message. The embodiments of the present application implement data splitting and handover processing for a next-generation mobile communication technology.