The invention relates to a stratum Q value calculation method based on a generalized seismic wavelet, and the method comprises the following steps: 1), pre-processing the collected zero-bias VSP data,performing wave field separation to obtain a VSP down-going wave record, and then using a window function to extract a direct wave of each channel; 2), dividing a subsurface medium into multiple stratums through the distance between the adjacent detectors in a well or a preset detector distance; 3), calculating the Q value of each stratum. Based on the generalized seismic wavelet hypothesis, thenew method starts from the propagation theory of a one-way wave in a viscoelastic medium, and achieves the calculation of the Q value of each stratum through the changes of the instantaneous frequencyat a wavelet envelope peak value. Because the generalized seismic wavelet has two flexible parameters (reference frequency and fractional order coefficient), the method can select the optimal parameters for the matching with the amplitude spectrum of an actual seismic wavelet, thereby enabling the estimation method to be good in wavelet adaptability, and improving the Q value estimation precision.