利用非均匀波导的多层分割法， 对传统 Ｗ Ｋ Ｂ法的相移值进行修正， 导出了改进的 Ｗ Ｋ Ｂ计算公式， 并给出相移修正值的计算公式。对常见的典型折射率剖面（指数型、高斯型、余误差型、截断线型）的数值计算表明， 该方法所得公式的精度远高于传统的 Ｗ Ｋ Ｂ近似， 在接近截止时仍与精确数值十分吻合。 The phase shift value of the traditional W K B method is modified by the multi-layer segmentation method of non-uniform waveguides, and the improved W K B calculation formula is derived and the formula for calculating the phase shift correction value is given. The numerical results of common typical refractive index profiles (exponential, Gaussian, residual error, truncated linear) show that the accuracy of the proposed method is much higher than the traditional W K B approximation, The value is very consistent.