Disclosed are a method, system and device for data transmission in the access point handover process, which is used to solve the problem existing in the prior art that interrupt delay of data plane will be increased when the access point handover is carried out in the case of heterogeneous network. The method of the embodiment of the present invention comprises: a user equipment determines that in the case that Radio Resource Control (RRC) connection remains the same, all or part of the Data Radio Bearers (DRBs) reconfigured from one cell to another cell is needed; the user equipment, in the access point handover process, transmits data through the original DRB, and the original DRB is the last used DRB before the data plane access point handover. The user equipment, during the access point handover process, transmits data through the original DRB, thereby reducing the interrupt delay of the data plane when the access point handover is carried out in the case of heterogeneous network, and further improving the handover efficiency and shortening the data transmission time.