Transfer radiometer is the critical calibration facility of remote sensing instruments on satellites to achieve spectral radiometric calibration on-orbit. It’s also the core for spectral calibration with high accuracy in the laboratory on earth. This paper compares the similarities and differences between several transfer radiometers developed by various institutes covering 200～700, 700～2 000 nm spectrum bandwidth separately through describing their construction, design and operational principles and the method of transferring radiometric calibration benchmark. It shows the realizable accuracy of every transfer radiometers by introducing their central technology applied in the calibration procedures of different wavelength range. The advantages and shortcomings together with every transfer radiometer determine the application circumstance. According to the introduction of the process of the calibration traceability based on radiance standard in international institutes of standard technology, it emphasizes the importance of transfer radiometers in the procedure. It demonstrates the significance of transfer radiometer in radiometric calibration of aeronautics and space through its application of monitoring the calibration light source for spectrometers. Finally, it presents the prospect for the development and crucial issues of transfer radiometer’s technology in the future research through describing the new transfer radiometer designed in internal institute. Simultaneously, it predicts and summarizes difficult problems required to be solved in the future as to high-accuracy calibration transferring system on-orbit against SI-traceable primary standard, which consists of cryogenic radiometers and transfer radiometers.