The bearings of liquid oxygen turbopump are the core components of the fuel delivery system of rocket engines and need to maintain stable operation under extremely low temperatures (liquid oxygen temperature reaching -183℃) and ultra-high-speed rotation (usually exceeding 20,000 RPM) conditions. In a liquid oxygen environment, traditional lubricants are prone to failure. Self-lubricating technologies, such as cage materials based on polytetrafluoroethylene (PTFE) or polyetheretherketone (PEEK), should be adopted to prevent low-temperature embrittlement. Bearing materials need to take into account both low-temperature toughness and wear resistance. Commonly used ceramic bearings are silicon nitride (Si3N4) or zirconia (ZrO2), or special alloy steel combined with low-temperature heat treatment processes.