Deflagration-hydraulic composite fracturing technology is a kind of reservoir reforming means that combines deflagration fracturing and hydraulic fracturing, which is to use the deflagration fracturing as a pre-fracturing, and extend the multiple radial fractures formed by deflagration fracturing in the near-well zone through the hydraulic fracturing. Based on continuum-discontinuum element method, the numerical simulation method of deflagration-hydraulic composite fracturing was constructed by considering quasi-static deflagration stress impact fracture creation, dynamic deflagrating gas fracture propagation, and dynamic hydraulic fracture propagation. The linear elastic constitutive is applied to the block element, the tensile-shear composite constitutive considering strain softening is applied to the interface element to simulate rock fracture, the Landau model is applied to describe the deflagration pressure change, and the fissure seepage satisfies the cubic law. The numerical model is verified by comparing it with the indoor explosion experiments, the analytical solution of gas flow and the approximate solution of fracture extension. Based on this model, the simulation of deflagration-hydraulic composite fracturing of straight wells and horizontal wells was carried out to analyze the characteristics of fracture propagation. And exploring the effects of initial stress difference, displacement and deflagration cluster spacing on fracture propagation in deflagration-hydraulic composite fracturing.