The invention discloses a tera-hertz photoelectric characteristic test system capable of realizing multiple test functions on photoelectric characteristics and the like of Fourier spectra, transmittance spectra, reflection spectra and tera-hertz electronic devices by combination of various customized light sources and detectors, light path components selected by a user, and addition of peripheralauxiliary equipment. The tera-hertz photoelectric characteristic test system has the advantages of high signal-to-noise ratio, high resolution, strong expandability, low cost and the like, and can bewidely suitable for tera-hertz technical research, new material research, environmental detection and biomedical analysis. In the tera-hertz photoelectric characteristic test system, the light paths,circuits and control of the spectra and photoelectric response test system are subjected to design optimization and systematic integration; compact and reasonable optical, mechanical and vacuum cavity structures are designed; computer controlled accurate mechanical scanning and data acquisition are adopted; and finally the aim of testing and analyzing tera-hertz photoelectric characteristics of materials and core devices such as tera-hertz light sources and detectors by using combination of various light sources and detectors can be fulfilled.