Based on finite element pre-processing software HyperMesh and SimLab, the finite element model of a four-cylinder diesel engine block was built, the characteristics of the two meshing tools were also be described. Using inhere free modal frequencies and shapes as evaluation indexes, the influences of cylinder block modeling methods were studied. By using HyperMesh combined with SimLab, an efficiency mesh generation method of cylinder block was proposed. This mesh generation method can also be used in the modeling of other complex parts.