A data transmission method, comprising: receiving (401, 502, 602, 702), by a second base station (1200, 1310), a first message from a first base station (1400, 1510), wherein the first message is used to request the second base station (1200, 1310) to allocate a radio resource, and the first message comprises resource scheduling information; determining (402, 503, 603, 703), by the second base station (1200, 1310), based on the resource scheduling information, a resource location of the radio resource and scheduling the radio resource; sending (403, 504, 604, 704), by the second base station (1200, 1310), a first response message in response to the first message to the first base station (1400, 1510); and receiving, by the second base station (1200, 1310), first time synchronization information from the first base station (1400, 1510); or, sending, by the second base station (1200, 1310), the first time synchronization information to the first base station (1400, 1510), wherein the first time synchronization information is used to indicate a time at which signaling transmission is started, and the first time synchronization information comprises a subframe index or a timestamp; characterized in that the first message is used to request the second base station (1200, 1310) to allocate the radio resource to a specific bearer; and in that the data transmission method further comprises: sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal, wherein the second message comprises radio resource configuration information determined by the second base station (1200, 1310) for the terminal; and receiving (508, 608, 708), by the second base station (1200, 1310), a second response message from the terminal in response to the second message, wherein the second response message is used to indicate that the terminal has completed radio resource configuration; wherein sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal comprises: sending, by the second base station (1200, 1310) and synchronously with the first base station (1400, 1510), the second message to the terminal at a time indicated by the first time synchronization information and at the resource location of the radio resource. receiving (401, 502, 602, 702), by a second base station (1200, 1310), a first message from a first base station (1400, 1510), wherein the first message is used to request the second base station (1200, 1310) to allocate a radio resource, and the first message comprises resource scheduling information; determining (402, 503, 603, 703), by the second base station (1200, 1310), based on the resource scheduling information, a resource location of the radio resource and scheduling the radio resource; sending (403, 504, 604, 704), by the second base station (1200, 1310), a first response message in response to the first message to the first base station (1400, 1510); and receiving, by the second base station (1200, 1310), first time synchronization information from the first base station (1400, 1510); or, sending, by the second base station (1200, 1310), the first time synchronization information to the first base station (1400, 1510), wherein the first time synchronization information is used to indicate a time at which signaling transmission is started, and the first time synchronization information comprises a subframe index or a timestamp; characterized in that the first message is used to request the second base station (1200, 1310) to allocate the radio resource to a specific bearer; and in that the data transmission method further comprises: sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal, wherein the second message comprises radio resource configuration information determined by the second base station (1200, 1310) for the terminal; and receiving (508, 608, 708), by the second base station (1200, 1310), a second response message from the terminal in response to the second message, wherein the second response message is used to indicate that the terminal has completed radio resource configuration; wherein sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal comprises: sending, by the second base station (1200, 1310) and synchronously with the first base station (1400, 1510), the second message to the terminal at a time indicated by the first time synchronization information and at the resource location of the radio resource. sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal, wherein the second message comprises radio resource configuration information determined by the second base station (1200, 1310) for the terminal; and receiving (508, 608, 708), by the second base station (1200, 1310), a second response message from the terminal in response to the second message, wherein the second response message is used to indicate that the terminal has completed radio resource configuration; wherein sending (506, 606, 706), by the second base station (1200, 1310), a second message to a terminal comprises: sending, by the second base station (1200, 1310) and synchronously with the first base station (1400, 1510), the second message to the terminal at a time indicated by the first time synchronization information and at the resource location of the radio resource.