The vertical hydraulic fracture behaviours when the fracture reaches stratum interfaces is studied. The pore pressure nodes constraint method is introduced to realize the numerical simulation of ǂ-shaped hydraulic fracture. The hydraulic fracture morphological characteristics and its damage evolution propagating process are studied. Combining with the injection pressure characteristics, the propagation history of the ǂ-shaped hydraulic fracture is studied. The morphological characteristics of hydraulic fracture when different fluid injection rates are well studied.