The invention relates to a time-frequency analysis method and a time-frequency analysis system for intruding waves of power transformation equipment. The time-frequency analysis method comprises the steps of acquiring intruding wave signals of the power transformation equipment in real time; recording the time-frequency waveform of the intruding wave signals by using an overvoltage measuring sensor; carrying out transformation on the time-frequency waveform of the intruding wave signals by using a preset alpha value, and acquiring time-varying waveform time-frequency characteristics of different frequency components of the intruding waves, wherein the transformation formula is shown in the description. According to the time-frequency analysis method and the time-frequency analysis system for the intruding waves, the intruding wave signals of the power transformation equipment are acquired in real time, the time-frequency waveform of the intruding wave signals is acquired, and transformation is carried out on the time-frequency waveform of the intruding wave signals by using the preset alpha value so as to acquire the waveform time-frequency characteristics, thereby overcoming deficiencies of traditional Fourier transform, being capable of retaining time and frequency information at the same time, reflecting local frequency characteristics of the signals, and thus providing important reference for mastering the waveform time-frequency characteristics of intruding waves of a power grid and determining voltage and frequency characteristic parameters of the intruding waves in follow-up experimental research.