A method for mitigating interference is provided. First, a received signal having a training sequence is received from a transmitter. Then, a Signal-to-Interference-plus-Noise Ratio (SINR) of the training sequence in the received signal is calculated, and whether a co-channel interference signal exists in the received signal is determined according to the SINR. The signal power corresponding to each time index in the received signal is calculated to detect a beginning time point and an ending time point of the co-channel interference signal. Finally, when the co-channel interference signal in the received signal is detected, the time when an interference cancellation filter is turned on is determined by the beginning time point and the ending time point.