LNG tanks are the key equipment for LNG plants and terminals. Reliability of LNG storage tank safeguarding system design is directly related to the safe running of plant in case of emergency. Through the comprehensive analysis on design principles, scheme setting, operation and equipment selection of LNG storage tank level protection system, pressure protection system, leakage alarm system, combustible gas detection and alarm system, fire system and other safety systems, this paper puts forward the design concept for each protection system of LNG storage tank on the basis of assessment and analysis of safety integrity level, which provides reference for the design of similar LNG storage tank safeguarding system and guidance for the management of safe and stable operation of tanks in LNG plant.