The embodiment of the invention provides an optical device spectral response measurement device and method. The device comprises an electro-optic phase modulator which is used for receiving an original electric signal generated by an electric signal generation module, carrying out phase modulation on the original electric signal to an original optical signal generated by an optical signal generation module, obtaining an original double-sideband phase modulated signal and outputting the signal, wherein the original electric signal is a combined signal of a microwave constant frequency signal and a microwave sweeping frequency signal; a photoelectric detector which is used for receiving a converted double-sideband phase modulated signal output by a to-be-tested optical device according to the received original double-sideband phase modulated signal, carrying out photoelectric conversion on the converted double-sideband phase modulated signal, obtaining a converted electric signal and outputting the signal; and a data processing module which is used for receiving an amplitude frequency signal and a phase frequency signal and respectively converting the signals into amplitude responseand phase response of spectral response, wherein the amplitude frequency signal and the phase frequency signal are extracted by a detection module from the converted electric signal through utilization of a frequency doubled signal analyzed from the microwave sweeping frequency signal.