Disclosed in the present invention is a phase delay extraction and compensation method in a PGC phase demodulation method, comprising: converting, by means of an analog-to-digital converter, an amplified and filtered sinusoidal phase modulation interference signal into a digital interference signal, simultaneously performing quadrature downmixing of first-order, second-order and fourth-order harmonics on the digital interference signal, so as to obtain three pairs of quadrature harmonic amplitude signals, using the three pairs of quadrature harmonic amplitude signals to extract a phase delay amount, using the phase delay amount to calculate a corresponding phase delay correction coefficient, multiplying the phase delay correction coefficient by a corresponding absolute harmonic amplitude signal equal to the sum of the absolute values of the quadrature harmonic amplitude signals, obtaining a new harmonic amplitude signal which is not affected by the phase delay, and then obtaining, by means of an arc tangent operation, a phase to be measured. The present invention solves the problems in the PGC phase demodulation technology of the difficulty in accurately measuring the phase delay and the difficulty in performing real-time compensation on the non-linear error caused by the phase delay, improving the phase measurement accuracy; and is widely used in the technical field of sinusoidal modulation interference.