以自由装填式药柱常用的丁腈橡胶（NBR）、三元乙丙橡胶（EPDM）包覆层为研究对象，采用数值分析与试验研究相结合的方法，研究不同厚度、不同尺寸缺陷离面位移和真空加载压差的关系。对影响检测灵敏度的错位距离进行分析，介绍了错位散斑图像上缺陷大小的测量方法以及药柱表面的处理方法。研究内容对自由装填式药柱包覆层黏接质量的激光错位散斑检测有实际参考意义。

The paper sets the nitrile-butadiene rubber(NBR) and the Ethylene propylene diene monomer(EPDM) film which has been widely used as an inhibitor in the free loading powder charge as the research target, for the different sizes defect with different depths,the relationship between the out-of-plane displacement and the vacuum loading different pressure was studied with numerical analysis and experiment methods. The magnitude of the image shear was analysed,because it controls the measurement sensitivity of shearography. The method of defect measurement and powder surface treatment method was described. The research content has practical reference significance for the laser shearography detection of the cladding bonding quality of free loading powder charge.