The invention relates to an adjacent channel interference elimination device and a method thereof for transmitting television signals, wherein the adjacent channel interference elimination device comprises a power detection unit, an interference elimination unit, a frequency shifter and a filter, wherein the power detection unit is used for detecting power of the television signals and judging whether adjacent channel signals cause strong adjacent channel interference on useful signals or not; the interference elimination unit comprises a frequency shifter and a filter; the frequency shifter is used for shifting the frequency of the television signals according to the power bandwidth of the filter when the power detection unit detects the adjacent channel signals which cause strong adjacent channel interference and for moving the adjacent channel signals which cause strong adjacent channel interference in the television signals to a stop band position beyond the power bandwidth of thefilter; and the filter is used for filtering the adjacent channel signals at the stop band position according to frequency shifting results. The adjacent channel interference elimination device and the method thereof provided by the invention can eliminate the adjacent channel interference effectively with simple structure and lower computation complexity, and therefore, a receiver can obtain good-quality television signals.