A carbon nanotube-based ternary comparator including a first decoder, a second decoder, and a comparison circuit. The comparison circuit includes: a first comparison unit for producing a greater-than-or-equal-to signal, and a second comparison unit for producing a less-than-or-equal-to signal. A first two-bit ternary signal is input into the signal input terminal of the first decoder. A first three-bit binary signal and a phase inverted signal of the first three-bit binary signal are output from a signal output terminal of the first decoder. A second two-bit ternary signal is input into the signal input terminal of the second decoder. A second three-bit binary signal and a phase inverted signal of the second three-bit binary signal are output from the signal output terminal of the second decoder.