The research on the characteristics of Arctic climate change under the background of future warming is of great significance. This research studies the spatio-temporal variability of Arctic 2-m temperature in the 21st century under the SSP2-4.5 scenario based on the climate models with better simulation of Arctic climate change in the Coupled Model Intercomparison Project Phase 6 (CMIP6). The results are as follows. (1) The Eurasia (EA) part and the North America-Greenland (GL) part of the polar continent show different responses to global warming. EA has a significant warming trend before the middle of the 21st century, and then mainly shows the interdecadal oscillations; GL maintains a warming trend. The temperature in the EA part and the GL part fluctuates on interannual and interdecadal (10-20 a) scales, and there is also a quasi-periodic variation of 20-40 a in the GL part. (2) The positive phase of the North Atlantic Oscillation in the previous winter can cause the North Atlantic to present a south-north “-, +, -” tripolar sea surface temperature anomaly (SSTA) in the next summer, and leads to a positive temperature anomaly in the EA part by affecting the atmospheric circulation, and the effect is mainly reflected on the interdecadal scale. (3) When the Atlantic Multidecadal Oscillation is positive, the geopotential height from North America to Greenland is high, the GL part warms, and this effect is more important after the 2070s. The positive SSTA in the north of the North Pacific also contributes to the warming in the GL part.