The invention discloses a device and method for measuring the relative spectral response of a wide-band imaging sensor, which can be used for spectral calibration of various wide-band imaging sensors, and solves the problem of measuring the spectral response of the imaging sensor in the prior art. Traditional spectral calibration light sources cannot meet the requirements of measuring the relative spectral response of different spectral resolutions and spectral ranges, or the spectral resolution and luminous flux are low. The device comprises a calibration light source, an optical filter, a homogenized cylindrical light guide tube, a diaphragm, a collimating mirror, a time modulation interferometer, an integrating sphere and a wide-band imaging sensor arranged in sequence along the optical path. At the same time, the invention also proposes a relative spectral response measurement method of a broadband imaging sensor, which uses a broadband calibration light source to generate time-domain interference signals, and has the technical advantages of high throughput and high spectral resolution.