The invention discloses a decoding method and a decoding device. The decoding method is based on at least one sub-decoder, and each sub-decoder can perform serial decoding treatment on N decoding sub-data blocks. The decoding device comprises at least one sub-decoder, and each sub-decoder can perform serial decoding treatment on N decoding sub-data blocks; the sub-decoder comprises an input module, a decoding module and an output module. In the decoding device, each sub-decoder can perform serial decoding treatment on N decoding sub-data blocks, and in the decoding process, the data in different decoding sub-data blocks can be decoded at the same time during each clock period, and compared with the prior art in which only one data can be decoded during each clock period and one data can be completely decoded during a plurality of clock periods, the embodiment of the invention improves the decoding throughput rate of Turbo codes on the premise of not increasing consumption of logic resources.