Objective To investigate whether there are changes in cognitive control among Tibetan indigenous residents exposed to long-term high altitude. Methods The Backward Masking Majority Function Task (MFT-M) was used to collect the capacity of cognitive control (CCC) of 93 Tibetans living in different high-altitude areas (2900m, 3700m, 4200m) and 92 Han people controls living in the plain. Results There were significant differences in CCC of the four groups. Specifically, the CCC of the plain control group and the 2900-m group was significantly higher than that of the 3700-m and 4200-m groups. However, there were no significant differences in CCC between the plain control group the 2900-m group as well as between the 3700-m and 4200-m group . Conclusion Long-term high-altitude exposure began to have negative impact on the capacity of cognitive control of Tibetan residents at altitudes between 2900-m and 3700m, indicating that 2900-m to 3700-m was the altitude threshold for CCC decline in Tibetan residents.