The present disclosure relates to the field of wireless communication technology, and provides a data transmission method and a data transmission device, so as to solve the problem in the related art where, for 5G application scenarios, in the case that an uplink scheduling algorithm for a conventional 4G system continues to be used, a large number of control signaling overheads are required due to the meteoric growth in the number of UEs to be connected. In the present disclosure, a network side device determines non-orthogonal multiple access basic transmission units allocated to UEs, detects a pilot signal from each UE on the corresponding non-orthogonal multiple access basic transmission unit, and in the case that the pilot signal has been detected, performs data detection on the UE which has transmitted the pilot signal through the non-orthogonal multiple access basic transmission unit.