Sensitivity analysis reveals that the side dead layer thickness, germanium crystal radius, crystal height, copper radius, and source-detector distance are five key parameters in the determination of DE profiles with different energy selectivity characteristics. After the optimization, the difference between the calculated and measured DEs is reduced to less than or equal to the measurement uncertainty of the measured DEs. Therefore the optimized model can be applied to the efficiency calibration of the above-mentioned detector system to improve its measurement accuracy. Finally, three group intelligence algorithms present satisfactory optimization capability and convergence rate, and the method developed in this paper can be extended to other HPGe systems.