To accurately predict the storage life of hydroxyl-terminated polybutadiene(HTPB)coating in solid rocket motor, accelerated aging tests at 50, 60, 70 ℃ and 80 ℃ were carried out. Logarithmic model, power function model and exponential model were used to study the maximum elongation of HTPB coating with storage time. Kooij equation was regarded as the aging model, and the storage life of HTPB coating at normal temperature was predicted. Results show that the power function model with α = 0.4 can describe the variation law of maximum elongation with time. The apparent activation energy of the aging reaction obtained is 29 kJ mol^-1 approximately, which is far less than 60 kJ mol^-1, revealing that the aging reaction during 50 ℃ to 80 ℃ is easy to occur. Taking the maximum elongation decrease of 50% as the failure criterion, the storage life of the estimated HTPB coating at normal temperature is 15.62 years, which can meet the aging performance requirements of the coating.