The invention discloses a method and a device for detecting interference signals. The method comprises the following steps: dividing received radio-frequency signals into two paths: I and Q, and differing the phases of the two paths of signals by 90 degrees; inputting the signals of the I path to a first LPF, inputting the signals of the Q path to a second LPF, and setting the bandwidth of the first LPF to be always greater than that of the second LPF; judging whether the total power of the signals of the I path, which are outputted by the first LPF after filtering is greater than the total power of the signals of the Q path, which are outputted by the second LPF after filtering, and judging whether the comparison value of the total power of the two paths of signals is greater than a preset ACI determination threshold; and if so, determining that ACI signals exist. The invention has simple hardware structure and simple and convenient implementation.