Fracture system plays a very important role in the enrichment and accumulation of oil and gas in the reservoirs． Based on scattering wave information， Fracture Orientation Function (FOF) was built， which can be used to predict the fracture orientations． However，this method has only been verified by physical experiments without studies on the application scope． In this study， based on the linear sliding theory， FOF of the scattering wave was applied to the numerical simulation and the application scope was further studied according to fracture flexibility tensor． According to the fractures filled with gas and liquid， numerical simulation was conducted on the models with various fracture flexibilities． Numerical simulation results were used to inverse fracture orientation with the aid of the FOF of the scattering wave． The results show that it is workable to predict the vertical fracture orientation with the FOF of the scattering wave． Application of this method is more effective when the fractures are filled with gas than liquid． Moreover，the application scope can be predicted by the fracture flexibility．