High altitude has a certain influence on the use of medium voltage gas-filling vessel under such conditions due to its unique climate environment. This paper points out the specific influence of high-altitude external environment on medium voltage gas-filling vessel from four aspects by analyzing the climate characteristics of high-altitude area and combining with the characteristics of medium voltage gas-filling vessel. Therefore, the technical requirements for the design of the medium voltage gas-filling vessel are put forward from the aspects of structural strength, mechanical properties, insulation properties and temperature rise performance of the gas-filling vessel, and the multi-class tests are comprehensively verified to ensure that the performance parameters of the medium voltage gas-filling vessel are within the design range, and then can be safely and reliably used in the appropriate high altitude environment.