The invention discloses a fractional order synchronous extraction 
generalized S transform time-frequency 
decomposition and 
reconstruction method. The method comprises the following steps: inputting x(t), selecting different rotation angles alpha to carry out 
fractional Fourier transform spectral analysis on x (t); selecting an optimal rotation 
angle alpha opt to carry out fractional order generalized S transformation on the 
signal to obtain a fractional order 
generalized S transform value, and performing modeling; solving fractional order instantaneous frequency 
estimation on the basis of thefractional order 
generalized S transform value, obtaining a synchronous extraction operator according to the instantaneous frequency 
estimation, extracting a fractional order generalized S transformtime-
frequency spectrum by using the synchronous extraction operator, retaining 
effective energy, and finally reconstructing a 
signal. According to the invention, the time-frequency characterization of the 
signal can be popularized to the time fractional order frequency characterization; time-frequency information details can be recognized by selecting the optimal rotation angle in a self-adaptivemode, on the basis, energy of a fractional order synchronous extraction generalized S transformation time-
frequency spectrum is more gathered by adjusting 
window function parameters and conducting extraction operation, and therefore the time-
frequency resolution of signals is greatly improved.