在全息干涉计量法获得的干涉光场相位中不同程度地存在散斑噪声，为顺利完成相位解包裹，降噪处理是必要的。通过剪切将噪声从光场中分离出来是一种有效方法，但剪切量的选择对去噪的影响还需要研究。通过理论分析、模拟计算和实验验证发现：剪切量会影响理想剪切光场相位与含噪声剪切光场相位之间的线性相关性，继而改变降噪难度；选取合适的剪切量可以使该线性相关系数达到最大，从而获得最佳的降噪效果。

As there exists speckle noise in the phase of optical field obtained from holographic interferometry, it is necessary to reduce noise so that phase unwrapping can be successfully completed. Separating noise from the optical field through shearing is an effective method, but the study on influence of shearing quantity selection is still needed. Through theoretical analysis, simulation computation and experimental validation, it is proved that shearing quantity has influence on the linear correlation between the phase of ideal shearing optical field and the phase of shearing optical field containing noise, and the difficulty of noise reduction is changed. The phase linear correlation coefficient reaches a maximum through selecting appropriate shearing quantity, thus the best noise reduction result can be achieved.