For the accurate measurement of environmental X/γ radiation dose rate, the conversion from energy spectrum to dose rate is used. In this paper, the energy spectrum and dose value of the electrically cooled high-purity germanium detector (HPGe detector) in the energy range of 0.01-1.5 MeV are obtained by Monte Carlo simulation. And the method “Conversion of complete spectra without deconvolution” is used for energy spectrum-dose conversion study. It is found that the dose rate calculated by Conversion of complete spectra without deconvolution method is in good agreement with the simulated dose rate. Experimental verification was carried out in the standard radiation field (Co-60, Cs-137) of the environmental γ radiation air absorbed dose of the China Institute of Metrology, the result shows that in the energy range of 0.01-1.5 MeV, the error between the dose rate value obtained by energy spectrum-dose conversion and the standard dose rate value is less than ±10%. The study shows that it is feasible to solve the energy spectrum-dose (rate) conversion coefficient by the method “Conversion of complete spectra without deconvolution”.