Producing structured mesh at the immediate vicinity of the crack front for three-dimensional (3D) crack modelling is a very time consuming and difficult task. A geometry feature based method for 3D crack modelling based on virtual crack closure-integral method (VCCM) for the tetrahedral finite element is proposed, and the implementation details of employing tetrahedral finite elements for 3D crack modelling on the basis of ABAQUS are described. On this basis, a 3D crack analysis package is developed by applying the Python programming language combined with NumPy and SciPy to automate the whole process of crack problem analysis. The stability and robustness of the 3D crack automated modelling is improved by employing tetrahedral finite element. The numerical examples are in good agreement with the results in the literature, proving the accuracy and reliability of the modelling method.