The invention relates to the technology of 
digital signal processing, and provides a self-adaptive high-precision fast 
spectral analysis method which solves the problem that an existing 
spectral analysis method is large in error and poor in precision. According to the technical scheme, the self-adaptive high-precision fast 
spectral analysis method comprises the steps of firstly collecting analog signals, carrying out preprocessing of 
smoothing, and then carrying out analog-
digital conversion to obtain sampling data; selecting 28 data to carry out FFT 
processing to obtain preliminary 
signal frequency spectrum information, carrying out peak searching, and then carrying out 
spectral line aliasing recognition on the preliminary 
signal frequency spectrum information; if 
aliasing does not exist, carrying out 
frequency spectrum correction 
processing on the preliminary 
signal frequency spectrum information to obtain the frequency, the amplitude and the 
initial phase information of the signals; if the 
aliasing exists, carrying out repeated analysis band-pass filtering 
thinning processing on the preliminary 
signal frequency spectrum information, and then carrying out the frequency spectrum correction processing to obtain the frequency, the amplitude and the preliminary phase information of the signals respectively. The self-adaptive high-precision fast spectral 
analysis method has the advantages that under the premise that calculation precision is ensured, the calculation amount is reduced to a large extent, and the self-adaptive high-precision fast spectral 
analysis method is suitable for spectral analysis.