The mechanisms of human cerebral cortex folding and their interactions during brain development are largely unknown, partly due to the difficulties in biological experiments and data acquisition for the developing fetus brain. Computational modeling and simulation provide a novel approach to the understanding of cortex folding processes in normal or aberrant neurodevelopment. Based on our recently developed computational model of the cerebral cortex folding using neuronal growth model and mechanical skull constraint, this paper presents a computational dynamic model of the brain skull that regulates the cortical folding simulation. Our simulation results show that the dynamic skull model is more biologically realistic and significantly improves our cortical folding simulation results. This work provides further computational support to the hypothesis that skull is an important regulator of cortical folding.