A Shifted Dual Transmission Grating (SDTG) component has been designed and fabricated in this work,a range of 0.1~5keV time-resolved spectrum can be recorded when the SDTG coupled with a streak camera. This SDTG is composed of 2000 lines/mm and 5000 lines/mm sub transmission grating which shifted with a certain distance. One of this sub grating is designed to measure the soft X-ray spectrum in 100~1000eV photon energy while the other measures 1000~5000eV photon energy. This space-shifted grating can sufficiently use the limited recorded panel to obtain a spliced time-resolved spectrum in streak camera. In this paper,The SDTG component is calibrated to get the diffraction efficiencies on Beijing synchrontron radiation facility,and the related efficiencies was achived. According to the structure parameter of this grating,the absolutely diffraction efficiency value was enentually obtained in combination the experimental values with the rigorous coupled-wave anslysis,meanwhile a method is discussed to unfold the source spectrum from the obtained efficiency. This SDTG component can improve the performance of the spectrometer,and may become an outstanding device to precisely measure x-ray spectra in the diagnostics of laser-produced plasma.