The identification of modal parameter for engine crankshaft in the free and fixed state was carried out. It was found that the boundary condition of crankshaft had great influence on the modal parameters. The hybrid modeling method of crankshaft test mode and simulation model was studied and the modal results in the constrained mode were acquired. The results show that the hybrid modeling method can convert the free mode results of crankshaft into the constrained mode that corresponds to the real fixed state in order to evaluate the dynamic characteristics of actual crankshaft operating process. In addition, it is confirmed that the in-cylinder pressure has less influence on the crankshaft restraint mode. The hybrid modeling method has the advantages of both experiment and simulation, improves the analysis accuracy of crankshaft constrained mode and reduces the test constraints, which provides more accurate conditions for evaluating the crankshaft dynamic performance and analyzing engine dynamic characteristics.