The invention proposes an elastic fracture simulation method based on a dual boundary element and strain energy optimization analysis. The two basic problems related to three-dimensional linear elastic fracture are handled. A model containing an overlapped cleft surface is expressed by using a dual boundary element method, and a super-singular boundary integral equation is solved by using a semi-analytic method. The continuous attribute from the contact load and released by the strain energy at the front end of the crack is represented by introducing a contact force model. A fracture factor ofthe extension distance of the crack is calculated within the fracture duration to perform accurate control on the extension of the cracking end.