The invention provides a method and a system for resonance detection of a multi-inverter power grid, a terminal and a storage medium. The method comprises the steps of collecting a to-be-detected original signal, and creating a window signal of the original signal; calculating a frequency domain form of the window signal according to a time domain convolution theorem for Fourier transform and a product, and obtaining a time domain form of the window signal by performing an inverse Fourier transform on the frequency domain form of the window signal; calculating a product of the original signaland the window signal in the time domain form in a frequency domain according to the original signal and the time domain form of the window signal, wherein the product is used as a detected oscillation frequency band signal; extracting a first frequency corresponding to an initial value angular velocity in the oscillation frequency band signal and a second frequency orthogonal to the first frequency, and calculating an amplitude value corresponding to the initial value angular velocity according to the first frequency and the second frequency; and constructing an angular velocity progressive formula according to the first frequency, the second frequency and the amplitude vale, calculating the angular velocity corresponding to the oscillation frequency, converting the corresponding angularvelocity to the oscillation frequency, and outputting the oscillation frequency.