To study the damage evolution and ductile fracture behavior of high-strength steel sheet under cold forming, we proposed a semi-coupled ductile fracture criterion. The DF2012 ductile fracture criterion was modified as the initial damage criterion. On the basis of the continuum damage mechanics (CDM) theory, the damage variable D was introduced to measure the cumulative damage of the material, and was coupled to the plasticity model. Taking TRIP780 high-strength steel as research object, six types of specimens were designed for different stress states. The resistance damage measurement and DIC digital image method were utilized to test the mechanical properties and initial damage displacement of specimens. The Drucker anisotropic yield function with non-associated flow rule (NAFR) and the Swift-Voce hardening model were used to accurately describe the plastic deformation process of the material. The initial damage model and the damage evolution parameters were calibrated by the hybrid test-simulation method and the inverse engineering method respectively. The constructed constitutive model and damage evolution model were compiled into the VUMAT subroutine using Fortran and implemented in the ABAQUS/Explicit module for fracture prediction, which were then compared with uncoupled damage model. Results show that the constructed semi-coupled ductile fracture criterion could accurately predict the damage-induced softening of TRIP780 sheets under different stress states. The maximum relative error of predicted damage displacement was only 1.31%. Compared with the commonly used uncoupled fracture model, the proposed model showed obvious superiority for high-strength steel with softening effect, which is suitable for fracture prediction in cold stamping forming of high-strength steel sheets.