The invention provides a high-speed parallel decision feedback equalizer, an equalizing method, and a channel interface module. The equalizing method comprises the steps of obtaining an initial decision set at each interval of a plurality of continuous time intervals. Each ininital decision shows that the hypothetic sequence of the former symbol decision leads to the inteference of the following symbols. The equalizing method also comprises the steps of forming a parallel set from the initial decision set; applyin ghte parallel set to a pipeline decision-feedback equalizer (DFE) multi-path multiplexer unit set. Each DFE multi-path multiplexer unit selects a symbol decision from each initial decision set to form a set of symbol decision. Based on the actual sequence of the symbol decision, one of the sets of the symbol decision is selected to be used as an acutal symbol decision. The invention overcomes the limit of data rate to the feedback signal.