A communication method, comprising: sending, by a user terminal, a first measurement report to a first base station, the first measurement report is used to determine a second base station that the user terminal is to preprocess, wherein the preprocessing comprises pre-handover to or pre-addition of the second base station, but does not comprise data transmission by using the second base station, and the first measurement report comprises signal quality information of a current serving cell and signal quality information of a neighboring cell of the current serving cell; receiving, by the user terminal, a preprocessing indication message sent by the first base station; sending, by the user terminal, a random access request to the second base station; and receiving, by the user terminal, a second indication message sent by the first base station, and implementing data transmission between the user terminal and the second base station based on the second indication message; characterized in that the user terminal is connected to the first base station by using a first component carrier; the received preprocessing indication message comprises information about a second component carrier on which the user terminal performs uplink synchronization with the second base station when performing the preprocessing, and the second component carrier is different from the first component carrier; and the sending, by the user terminal, the random access request to the second base station comprises: sending, by the user terminal based on the preprocessing indication message, the random access request to the second base station on the second component carrier, to implement the preprocessing on the second base station; wherein the preprocessing indication message or the second indication message further comprises signaling radio bearer, SRB, configuration information and data radio bearer, DRB, configuration information that are pre-configured by the second base station for the user terminal; and the receiving, by the user terminal, a second indication message sent by the first base station, and implementing communication between the user terminal and the second base station based on the second indication message comprises: receiving, by the user terminal, the second indication message sent by the first base station, and establishing an SRB and a DRB between the user terminal and the second base station based on the SRB configuration information and the DRB configuration information in the preprocessing indication message or the second indication message, to implement data transmission with the second base station. sending, by a user terminal, a first measurement report to a first base station, the first measurement report is used to determine a second base station that the user terminal is to preprocess, wherein the preprocessing comprises pre-handover to or pre-addition of the second base station, but does not comprise data transmission by using the second base station, and the first measurement report comprises signal quality information of a current serving cell and signal quality information of a neighboring cell of the current serving cell; receiving, by the user terminal, a preprocessing indication message sent by the first base station; sending, by the user terminal, a random access request to the second base station; and receiving, by the user terminal, a second indication message sent by the first base station, and implementing data transmission between the user terminal and the second base station based on the second indication message; characterized in that the user terminal is connected to the first base station by using a first component carrier; the received preprocessing indication message comprises information about a second component carrier on which the user terminal performs uplink synchronization with the second base station when performing the preprocessing, and the second component carrier is different from the first component carrier; and the sending, by the user terminal, the random access request to the second base station comprises: sending, by the user terminal based on the preprocessing indication message, the random access request to the second base station on the second component carrier, to implement the preprocessing on the second base station; wherein the preprocessing indication message or the second indication message further comprises signaling radio bearer, SRB, configuration information and data radio bearer, DRB, configuration information that are pre-configured by the second base station for the user terminal; and the receiving, by the user terminal, a second indication message sent by the first base station, and implementing communication between the user terminal and the second base station based on the second indication message comprises: receiving, by the user terminal, the second indication message sent by the first base station, and establishing an SRB and a DRB between the user terminal and the second base station based on the SRB configuration information and the DRB configuration information in the preprocessing indication message or the second indication message, to implement data transmission with the second base station.