The induced condition and mechanical mechanism of hydraulic fracturing is briefly analysed. Based on the triangle fracturing under water pressure and finite element method
an approach is suggested to judge the occurrence of hydraulic fracturing. In this approach it is assumed that there exist local permeable weak planes (cracks) in core; and the plane finite element method (FEM) for hydraulic fracturing analysis is established. The crack is taken as a soft material; and the effect of water pressure acting on both sides of the crack is modeled. By using FEM
the stress of element at the crack tip is obtained; and the possibility of hydraulic fracturing is judged. This approach can also simulate the development of hydraulic fracturing.