利用滤波荧光(FF)法建立了5~88 keV能区硬X光能谱测量系统，对闪烁探测器的灵敏度进行了精密标定，不确定度好于10%。通过研究干扰产生的原因，改善系统屏蔽，有效地排除了干扰，提高了系统的信噪比;通过更换大电流的光电倍增管，改变准直光阑的尺寸和滤片的厚度，将测量系统的线性动态范围从4提高到104。在神光Ⅲ原型物理实验中定量给出Au平面靶硬X光谱，实现硬X光能谱的精密测量。

Suprathermal electron is an important factor influencing ignition in inertial confine fusion. Measuring results of hard X-ray spectrum could get suprathermal electron temperature and suprathermal electron quantities. This project mainly built a system to measure hard X-ray spectrum in energy region of 5 keV to 88 keV utilizing filter-fluorescer method. The system accurately calibrated its scintillator’s sensitivity with an uncertainty of less than 10%. System signal-to-noise ratio was increased by shielding the interference from system insides and environment of measurement. System output linearity was enhanced from 4 to 104 by replacing a photo-multiple-tube which could stand bigger current and changing the size of aperture or filter’s thickness. Finally, the system succeeded in measuring a precise hard X-ray spectrum of Au-plane target in SG-Ⅲ prototype.