本文提出一种按速度模型计算绕射波射线旅行时和进行绕射归位的方法。偏移归位的结果直接为深度剖面。该法既可用于迭后偏移,也可用于迭前偏移。对地质结构复杂地区,该法可以避免某些不适当的近似假设条件。文中还通过一个理论模型的计算来说明这种方法的效果。 In this paper, we propose a method to compute diffraction and ray hits based on velocity model when traveling and performing diffraction homing. The result of offset homing is directly the depth profile. This method can be used for post-lag migration, can also be used for pre-migration. For complex geological structures, the law can avoid some inappropriate approximate assumptions. The article also shows the effect of this method through the calculation of a theoretical model.