The invention provides a partial discharge positioning method and system for an electrical device, a storage medium and a terminal device. The method includes the steps of obtaining a harmonic frequency cutoff frequency of a power frequency of a sound pressure signal of an electrical device; filtering the sound pressure signal of the electrical device by using a linear phase shift multi-stop bandcomb filter pair to obtain a residual signal obtained by filtering out the harmonic frequency of the power frequency; calculating the kurtosis of the residual signal and setting a kurtosis threshold;if the kurtosis is greater than the kurtosis threshold, then determining that partial discharge occurs within a time period corresponding to the kurtosis; generating a partial discharge signal including phase characteristics based on the determined time period of the partial discharge and a partial discharge signal model; and achieving partial discharge positioning according to the phase characteristics of the partial discharge signal. The partial discharge positioning method and system for the electrical device, the storage medium and the terminal device in the invention can realize the accurate and rapid positioning of the partial discharge of a substation.