Abstract: Simultaneous fracturing process is a new technique for reservoir improvement of unconventional gas, such as shale gas and coal bed methane. Revealing the mechanical mechanism of fracture propagation is the basis of optimizing treatment parameters. The study shows that multi?fracture simultaneous propagation may alter the stress field and these fractures can interact with natural fractures. Both of them co-determine the pattern of fracture network during the fracturing process. Fracture network engineering (FNE) is the best method for study of such a model for fractures propagation at present. To achieve complex fracture networks by inducing in?situ stress field, the parameters such as number of fractures, distance between fractures, net pressure and the geometry of hydraulic fractures should be optimized