The invention provides a distribution network short circuit fault fast detection method based on real-time wavelet transform. The method comprises the steps that 1 sampling at fixed sampling frequencyis carried out on a three-phase current signal to acquire a three-phase current sampling signal, and then multi-scale wavelet transform is carried out on the three-phase current sampling signal to acquire third-phase wavelet coefficients under the third dimension, wherein the sum of the absolute values of the three-phase wavelet coefficients under the third dimension is the characteristic amountof a short circuit fault; and 2 the threshold value of the short circuit fault is set as T, and if the characteristic amount of the short circuit fault at any time exceeds T, the short circuit fault occurs in a distribution network. According to the invention, the short circuit fault in the distribution network line is fast identified.