根据衍射光学元件衍射效率的测量原理，建立衍射光学元件衍射效率测量的双光路装置，简要介绍了双光路测量的优点。针对衍射光学元件衍射效率的测量装置，讨论了影响衍射效率测量精度的因素，合理地选择测量装置中的针孔光阑，即可以让主衍射级次的光全部通过被探测器接收，又可以滤掉次级衍射光，保证测量结果的准确度。针对所设计研制的一个折衍射混合成像光学系统，测量了可见光波段3个激光波长的衍射效率，并对测量结果进行了模拟和分析。在473~632.8 nm波段范围内任意一个波长处，衍射效率的测量结果同理论值的偏差均小于5.0%。实验证明，双光路测量装置可以用于测量衍射光学元件的衍射效率。

According to the measuring principle of diffraction efficiency for diffractive optical elements, the double light-path measurement device of diffraction efficiency is set up. The advantages of double light-path measurement are briefly introduced. For the measurement device of diffraction efficiency for diffractive optical elements, the factors having influence on the accuracy of the measurement results are discussed by the reasonable choices of the pinhole aperture of the measurement device, the light of the main diffraction order can be received by the detector, and the secondary diffraction light will be filtered out, ensuring the accuracy of the measurement results. The diffraction efficiency of the designed hybrid refractive-diffractive optical system is measured at three laser wavelengths over the visible waveband. The measurement results are simulated and analyzed. The deviation of the measurement results from the theoretical value is less than 5.0% over the 473~632.8 nm waveband. The double light-path measurement device can be used to measure the diffraction efficiency of diffractive optical elements.