This paper presents the synthesis of a POSS-based supramolecular gel with polyalkylcyclopentane (MAC) as the base oil through molecular design, which exhibits excellent resistance to space atomic oxygen (AO) irradiation. Herein, the reduce-friction (RF) and anti-wear (AW) properties and the resistance to space AO irradiation of the gel were first systematically investigated under atmospheric and simulated space environments. The results demonstrate that effectively improves the RF and AW of MAC in atmospheric or simulated space environments due to the POSS structure and high load-carrying capability of silicon-containing compounds generated by tribochemical reactions, as well as effectively separates the direct contact of the friction interface. POSS gel shows excellent promise in being used as a lubricant in the space environment.