Abstract: In order to study the temperature separation characteristics of vortex tubes with different cold cone angles and improve the temperature control effect of natural gas wellhead throttling of vortex tubes, a numerical model of energy separation of vortex tubes with high pressure methane as working medium was established by using the standard k-ε turbulence model. The results show that with the increase of the cold cone angle, the static temperature and total temperature at different axial positions in the vortex tube first decrease and then rise. The flow patterns of forced vortex and free vortex are observed in the center and outside of the vortex tube, respectively. The tangential velocity and axial velocity show peak values near the wall surface. The cooling effect is positively correlated with the cold cone angle, while the heating effect is negatively correlated with the cold cone angle.