The invention discloses a rapid bus protection method based on comparison of similarity of contrary motion waveforms. The rapid bus protection method comprises the following steps: respectively reading the three-phase current of a bus and the original data of current at an end close to the bus, of an association circuit; carrying out phase-mode transformation on the three-phase current and the current at the end close to the bus by using a composite modulus method; respectively carrying out S transformation on corresponding initial voltage current motion waves so as to obtain S transformationcomposite matrixes; extracting reverse motion waves, and acquiring Euclidean distances of reverse motion waveform signals after faults of different association circuits; calculating the similarity ofdifferent circuits by using the Euclidean distances of the reverse motion wave signals of different association circuits; establishing protection criterions, and judging internal faults and external faults. By adopting the rapid bus protection method, by analyzing the similarity of waveforms of reverse motion waves of different association circuits after S transformation, internal faults and external faults of a bus area can be recognized, influence of factors such as transition resistance and initial angles of faults are generally overcome, internal faults and external faults of the bus areacan be accurately recognized, good interference resistance can be achieved, and rapid protection recover of buses can be facilitated.