The disclosure discloses a multi-antenna signal processing method in an uplink system. The method includes that: after scrambling, modulation, layer mapping, pre-coding, transmission pre-coding, resource mapping and Single Carrier Frequency Division Multiple Access (SC-FDMA) signal generation are performed successively on a coded bit sequence corresponding to each codeword, a resulted signal is transmitted from each transmitting antenna port. The disclosure also provides a multi-antenna signal processing device in an uplink system. With the method and the device according to the disclosure, a lower Peak-to-Average Power Ratio (PAPR) or Cubic Metric (CM) of a signal to be sent can be ensured without imposing any constraint on a pre-coding matrix, thus reducing the cost and power consumption of a terminal whiling increasing transmission performance of the system.