  A new cosmological model based on the de Sitter gauge theory (dSGT) is
studied in this paper. By some transformations, we find, in the dust universe,
the cosmological equations of dSGT could form an autonomous system. We conduct
dynamics analysis to this system, and find 9 critical points, among which there
exist one positive attractor and one negative attractor. The positive attractor
shows us that our universe will enter a exponential expansion phase in the end,
which is similar to the conclusion of $\Lambda$CDM. We also carry out some
numerical calculations, which confirms the conclusion of dynamics analysis.
Finally, we fit the model parameter and initial values to the Union 2 SNIa
dataset, present the confidence contour of parameters and obtain the best-fit
values of parameters of dSGT.
