An example of topology optimization is discussed in this paper, the finite element models are respectively created by linear elements and quadratic elements. Results show that the accuracy of quadratic element is higher than linear element, however, the calculating time of quadratic element model is longer, which causes the decreasing problem of efficiency. Compared with the quadratic element model, the bias of accuracy of the linear hexahedral and pentahedral element model are respectively 4.57% and 14.62%. Therefore, to complex models, it's necessary to create finite element models by the combination of kinds linear elements or the combination of quadratic and linear elements ,which improve the computing efficiency without losing accuracy.