[Background] The prompt gamma neutron activation analysis involves a gamma ray efficiency scale of the high purity germanium (HPGe) detector in the 0.1~11 MeV wide energy region that can be used to calibrate the detection efficiency when the low energy standard source is unavailable.[Purpose] This paper aims to obtain the key technical indicators of HPGe detectors,to determine the relative efficiency curve under limited condition.[Methods] A ~(157)Gd(n,gamma) source was employed to replace low energy standard source.Combined with ~(35)Cl(n,gamma) cold neutron prompt source and 152Eu delayed source,efficiency grading was carried out by using both piecewise fitting and global fitting methods.The fitting effect of ~(157)Gd(n,gamma) source was compared with that of 152Eu source.[Results] The experimental results show that the calculation of integral global fitting is relatively simple,but the data obtained by piecewise fitting is more accurate and have better correlation,hence better result of piecewise fitting is achieved with comparison of global polynomial fitting.The use of the ~(157)Gd(n,gamma) source worked well without the low energy standard source such as ~(22)Na,~(54)Mn,~(133)Ba,and the production efficiency calibration curve of HPGe detector was completed.[Conclusion] The piecewise logarithmic fitting method can be used to calibrate the detection efficiency of the all-energy peak in the wide-energy region of the electric refrigeration HPGe detector by using ~(157)Gd(n,gamma) source,which laid a solid foundation for future experiments such as neutron activation.