Beaufort Gyre (BG) had presented the significant changes associated with the complicated interactions between the Arctic air-ice-ocean system. In this paper, the observed McLane Moored Profiler data combined with the oceanic and atmospheric reanalysis datasets are used to discuss the influence of atmospheric momentum input on the BG long term changes. The BG exhibited the three different stages from 1980 to 2018 (1980−1995, 1996−2007, 2008−2018). The BG kept a stable state during the recent period (2008−2018). Compared with the first period (1980−1995), the BG strength reached up to 4.39×10⁻⁷, and increased nearly twice during the recent period. Meanwhile, the upper ocean processes showed the measurable discrepancies, such as the BG area expanded, gyre moved northwestward, and upper baroclinicity enhanced. Accordingly, the leading upper circulation mode had undergone a significant shift during these two periods. During the recent period, that is the leading Pacific sector mode played the main role in the upper circulation, while the basin mode receded the domination. Since the air-ocean stress represents the atmospheric momentum input process, our study indicated the summer air-ocean stress (August−October) increased remarkably and was even equivalent to the contribution of sea ice. The increased atmospheric momentum input may benefit to the mean kinetic energy increasing, together with the Ekman pumping enhancing and cold halocline deepening. Thus, the mentioned processes resulted in the BG obvious enhancement during the recent period. The southern Canada basin was the key area for the atmospheric momentum input.