Two-dimensional total routhian surface (TRS) calculations are carried out to determine the triaxial superdeformation (TSD) of the even-even nucleus W, and the result indicates that TSD state exists with deformation parameters ∊2 = 0.42 and γ = 34.7°. In the same way, the total routhian surfaces for the nuclei W are also calculated. It shows that the neutron shell correction energy plays a key role in the formation of TSD nuclei 172,174,176W, while the high j intruder orbitals and rotational energy are also crucial in the formation mechanism.