A data transmission method of a system, wherein the method comprises: monitoring, by a user equipment, UE, grant instruction delivered by an evolved NodeB eNB, wherein the grant instruction is used to instruct the UE to add uplink data to a designated resource, wherein the designated resource is a resource used for full-duplex transmission; and adding, by the UE, to-be-transmitted uplink data to the designated resource identified by the grant instruction, and transmitting the to-be-transmitted uplink data to the eNB; wherein the grant instruction is carried on a physical downlink control channel PDCCH of downlink subframes, or is carried on a PDCCH of uplink subframes; and wherein the grant instruction further carries control information and transmit power required for data transmission, and the method further comprises: adding, by the UE, the control information to the to-be-transmitted uplink data, wherein the control information is used to identify related information of the uplink data and a scheme used by the eNB to subsequently detect and parse the designated resource that carries the uplink data; and adding, by the UE, to the designated resource, the uplink data to which the control information is added, and transmitting the to-be-transmitted uplink data to the eNB based on the transmit power, and obtaining, by the eNB, the uplink data according to the control information. monitoring, by a user equipment, UE, grant instruction delivered by an evolved NodeB eNB, wherein the grant instruction is used to instruct the UE to add uplink data to a designated resource, wherein the designated resource is a resource used for full-duplex transmission; and adding, by the UE, to-be-transmitted uplink data to the designated resource identified by the grant instruction, and transmitting the to-be-transmitted uplink data to the eNB; wherein the grant instruction is carried on a physical downlink control channel PDCCH of downlink subframes, or is carried on a PDCCH of uplink subframes; and wherein the grant instruction further carries control information and transmit power required for data transmission, and the method further comprises: adding, by the UE, the control information to the to-be-transmitted uplink data, wherein the control information is used to identify related information of the uplink data and a scheme used by the eNB to subsequently detect and parse the designated resource that carries the uplink data; and adding, by the UE, to the designated resource, the uplink data to which the control information is added, and transmitting the to-be-transmitted uplink data to the eNB based on the transmit power, and obtaining, by the eNB, the uplink data according to the control information. adding, by the UE, the control information to the to-be-transmitted uplink data, wherein the control information is used to identify related information of the uplink data and a scheme used by the eNB to subsequently detect and parse the designated resource that carries the uplink data; and adding, by the UE, to the designated resource, the uplink data to which the control information is added, and transmitting the to-be-transmitted uplink data to the eNB based on the transmit power, and obtaining, by the eNB, the uplink data according to the control information.