The invention discloses a circuit breaker switching on / off coil turn-to-turn short-circuiting fault detection method and belongs to the electric power equipment detection technical field and electric power equipment application technical field. The method includes the following steps of: 1, tested coil design: two taps of the outgoing line of a tested coil are adjusted so that the length of the two taps can be inconsistent; 2, fault detection and signal acquisition: a double-ended pulse method is adopted to detect the tested coil, so that waveform signals can be obtained; and 3, fault analysis: noise reduction is carried out on the waveform signals obtained at the two taps respectively in the step 2, and subtraction is carried out on the waveform signals which are obtained from the two taps respectively and have been subjected to noise reduction, so that fault characteristic waveforms can be obtained, and the fault characteristic waveforms are analyzed through the following manners: when the subtracted fault characteristic waveforms are a straight line, a turn-to-turn short-circuiting fault does not occur, and when the subtracted fault characteristic waveforms have non-zero protruding regions, a turn-to-turn short-circuiting fault occurs. The circuit breaker switching on / off coil turn-to-turn short-circuiting fault detection method of the invention has the advantages of high sensitivity, portable equipment, simple analysis and operation, intuitive judgment and high reliability, and is more suitable for on-site application.