混合法偏移是一种将有限差分偏移和频率波数域偏移相结合进行偏移的方法，它兼有两者的优点，即既能适应较大横向变速情况，又节省内存和运算量。本文利用平方根算子的最佳逼近，导出了混合法偏移的一种新算法，其运算交替用ω－x域中的有限差分法和f-k是域中的相移法来完成。同时，还提出了一种新的吸收边界条件，它通过在边界外附加一个很薄的具有强吸收作用的边界层，并与衰减型吸收边界条件相结合，有效地消除了边界反射。该方法既适用于规则区域，又适用于不规则区域，其离散方程具有统一形式，易于编程。较多的模型计算和实际资料试算表明，该方法是一种计算量适中、处理精度高、稳定性好、吸收效果明显的偏移方法。 Hybrid method migration is a combination of finite difference and frequency wave number domain offset shift method, which combines the advantages of both, that is, not only to adapt to large lateral speed change, but also save memory and computation . In this paper, we use the square root of the best approximation to derive a new hybrid algorithm offset algorithm, the operation of alternating ω-x domain with the finite difference method and f-k is the domain phase shift method to complete. At the same time, a new absorption boundary condition is also proposed, which can effectively eliminate the boundary reflection by adding a thin boundary layer with strong absorption outside the boundary and combining with the absorption boundary conditions. The method is suitable for both regular and irregular regions. The discrete equation has a uniform form and is easy to program. More calculation of the model and actual data shows that this method is a migration method with moderate calculation, high precision, good stability and obvious absorption effect.