In order to study the anti-aging effect of the hindered phenolic on the crack sealant system, hindered phenol 1076, butylated hydroxytoluene (BHT) and hindered phenol 1010 were used to modify the as-prepared ordinary sealants. Under the field condition, the crack sealant systems before and after modification were aged. Then, the performance changes, viscoelastic characteristics of the crack sealant before and after aging were compared, and the structural was characterized. The results show that the crack sealant modified with hindered phenol 1076 sustains anti-aging effect within 12 h of aging time. Hindered phenol BHT effectively inhibits the formation of polar groups and the increase of sealant’s modulus within 6 h of aging time. However, after aging for long time, the anti-aging effect of hindered phenol BHT declines obviously. Hindered phenol 1010 effectively inhibits the formation of carbonyl group after aging for 12 h but exhibits insufficient anti-aging effect within 6 h aging time. The anti-aging effect of the antioxidants is affected by its molecular structure, migration and the compatibility with the crack sealant system. The high compatibility, low steric hindrance effect and low migratibility are helpful for hindered phenol to improve the anti-aging property of crack sealant stably and efficiently. Isophorone diisocyanate can effectively improve the dispersion of hindered phenol in the crack sealant, further improving the anti-aging effect of the sealant system.