从部分偏振散斑光场的统计理论出发，对像斑强度中心漂移进行了计算，导出了测量的基本不确定度的表达式，指出了在部分偏振光照明下有利于提高测量精度。 Based on the statistical theory of partial polarized speckle light field, the shift of intensity center of spot is calculated, and the expression of the basic uncertainty of measurement is deduced. It is pointed out that it is helpful to improve the measurement accuracy under the illumination of partially polarized light.