The invention discloses a channel decoding device and a method thereof, wherein, the device comprises a channel synchronous module which conducts coarse synchronization and judges signal structures; according to the judged results and the coarse synchronization results, the initial windowing position is determined and fraction frequency offset adjustment and integer frequency offset adjustment are carried out; by fine synchronization operation, an FFT accurate windowing position and channel model information are acquired and then sent to a Fourier-transform module and a channel estimation module. The Fourier-transform module conducts FFT transformation according to the windowing position and extracts load signals to sent thereof to the channel estimation module; the channel estimation module receives the load signals and the channel model information, separates the pilot frequency information and the load data in the load signals, conducts channel estimation according to the scatteredpilot frequencies in the channel model information and the pilot frequency information, and outputs the load data and channel estimators. The invention realizes the situation of supporting LCP and SCP simultaneously in an integral architecture.