Abstract: 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.