The permeability of unconventional oil and gas reservoir is inefficiency. Hydraulic fracturing produces the complex network of connected fractures as a prerequisite for efficient exploitation of unconventional oil and gas. The key factor affecting the formation of complex fracture network is the communication mechanism between hydraulic fracture and natural fracture. Based on the secondary development of ABAQUS software, discrete fracture network(DFN) model was established by using 0 thickness cohesive element, and acoustic emission simulation was used to detect the acoustic emission data in the whole fracturing. Based on the numerical simulation results and acoustic emission simulation results, the effects of displacement and in-situ stress conditions on the propagation process of hydraulic fractures were studied. The results show that the evolution of hydraulic fracture network is affected by displacement and in-situ stress difference. The smaller the difference of in-situ stress, the larger the width of the main fracture, and the easier to produce secondary cracks on both sides of the main fracture. The larger the difference in in-situ stress, the easier to produce hydraulic fractures, but the single fracture path is difficult to form a complex fracture network. The displacement becomes larger, so the hydraulic fracture starts earlier, the fracture propagates faster and the fracturing effect becomes better.