An equalizer circuit includes a first arithmetic circuit, a second arithmetic circuit, a data sampling circuit, and an edge sampling circuit. The first arithmetic circuit is configured to compensate an equalization sequence by secondary feedback sequences to output a first added sequence. The second arithmetic circuit is configured to compensate the first added sequence by a primary feedback sequence to output a second added sequence. The data sampling circuit samples, according to data clock, the second added sequence to output a primary sequence, and gains the primary sequence to output the primary feedback sequence. The data sampling circuit sequentially samples, according to the data clock, the primary sequence to output secondary sequences. The data sampling circuit gains the corresponding secondary sequences to output the secondary feedback sequences. The edge sampling circuit is configured to sequentially sample, according to an edge clock, the first added sequence to output an edge sequence.