In this paper, the Seismic risk in the middle of the Bayan Har block based on the profile likelihood estimation of the generalized Pareto distribution is studied. Earthquake samples in the middle of the Bayan Har block in the late 60 years are analyzed. The result shows that the area experiences an earthquake above 7.0 every 5 years. The theoretical upper limit of magnitude is 8.7, indicating frequent geological activities in this area. The profile likelihood estimation is consistent with the estimation of the maximum likelihood of the parameters. The confidence interval of the short-term return level is the same for the two methods. But with the increasing return period, the confidence interval obtained by the profile likelihood estimation is shifted to the right as a whole compared to that of the Delt method. The ratio of the confidence interval length on both sides of the return level will increase. This asymmetry is effective for the uncertainty of magnitude prediction.