The hygrothermal accelerated aging experiments for adhesive interface specimens of solid rocket motor were carried out, and the tearing strength at different aging time was measured. The phenomena in the hygrothermal accelerated aging experiments and tearing strength measurment were described and explained, also including the rule of variation of the tearing strength with aging time by contrasting to the absorption law of composite. The results show that the lining-propellant interfaces are the weakest interfaces. Hygrothermal aging can promote the diffusion and permeability of water from lining-propellant interface to propellant internal and lead the tearing strength loss. The average tearing strength of adhesion interface varies downward with aging time, and there is a period in which the strength varies stably.