The invention discloses a paper oil insulation extension Debye model parameter identification method based on a FDS. The method comprises the following steps: 1, performing frequency domain dielectricspectrum testing on a to-be-tested oil-immersed insulation sample to acquire a real part measured value and an imaginary part measured value of a complex capacitor; 2, establishing model equivalent complex capacitor real part C' and virtual C" expressions according to the extension Debye model so as to obtain a real part fitted value and an imaginary part fitted value of the complex capacitor; 3,establishing an identification target function of the extension Debye model parameter; and 4, performing iterative solution on the identification target function of the extension Debye model parameter by using an algorithm of combining a particle swarm algorithm with the least square method, thereby obtaining the final solution of the extension Debye model parameter. The invention puts forward amethod of constructing a paper oil insulation extension Debye model based on the frequency domain dielectric response technology FDS curve, so that the problems that the method of acquiring the equivalent model parameter by using the time domain dielectric response in the existing paper oil insulation equivalent model research is insufficient in reliability, and a time domain export model is bad in matching degree with the frequency domain dielectric spectrum and bad in stability can be effectively solved.