海底对浅海声传播的影响很大。海底有复杂的多层结构。在计算声场时如果把多层海底的影响都考虑进去,就会使计算复杂化,得不出一个清晰的物理图象。因此,在计算中往往使用海底反射损失系数来代替多层海底的模型。但海底反射损失与角度有复杂的依赖关系。为了计算方便,提出过不少简化模型。已经使用的模型有反射损失与角度无关、与角度一次方成正比;后来又提出反射损失在某一临界角之下与角度一次方成正比,在临界角之上与角度无关的三参数模型,克服了远场与近场衔接的问题。但这些模型不一定在所有情况下都能反映海底反射损失与角度的关系的主要特征。本文提出一个近似方法,可以计算海底反射损失按任意规律随角度单调上升的情况下的声场。如果知道均匀层浅海的传播衰减规律, Seabed has a great influence on the propagation of shallow sea sound. The sea floor has a complex multi-layer structure. Taking into account the effects of multiple layers of seafloor when calculating the sound field complicates the calculation and leaves no clear physical picture. Therefore, the seabed reflection loss coefficient is often used in the calculation to replace the multi-layer seafloor model. However, the loss of seafloor reflection has a complex dependence on the angle. For the convenience of calculation, many simplified models have been proposed. The model has been used in the loss of reflection has nothing to do with the angle, and the angle of the first-order proportional; later proposed a reflection loss under a certain critical angle proportional to the angle, above the critical angle angle independent of the three-parameter model, Overcome the far field and near field convergence problem. However, these models do not necessarily reflect in all cases the main features of the relationship between the loss and angle of seabed reflection. In this paper, an approximate method is proposed to calculate the sound field under the condition that the loss of seafloor reflection monotonously increases with the angle according to any law. If you know the uniform layer of shallow sea propagation attenuation law,