To quantify the impact of extremely cold environments on the DC fast charging performance of pure electric vehicles, this paper conducted a comparative test of DC fast charging on the same vehicle under normal temperature 25 ℃ and extremely cold conditions -25 ℃. The focus was on analyzing the differences in charging time, power, battery temperature rise, and energy consumption of the thermal management system. The results show that the charging time in the -25 ℃ environment is 3.8 times that in the 25 ℃ environment, and the initial charging power is severely limited; the highpower operation of PTC leads to an increase in total system energy consumption and a decrease in charging economy by approximately 13%. This paper provides measured data support for optimizing the fast charging strategy and designing the thermal management system of electric vehicles under extreme climates, and offers guidance for using vehicles in extremely cold regions.