To determine the reasonable integrity quality evaluation time of cement-treated aggregate base (CTAB) layers, eliminate the influences of curing conditions, gradation types, and design strengths (cement dosage), and make up the limitations of using fixed age to evaluate CTAB construction quality, large specimens with three types of gradations and three kinds of cement dosages were molded by vibration method for experiment. After using three kinds of curing paths to preserve, the coring and splitting strength tests were carried out, and the relationship between maturity and splitting strength was established. Experiment results show that cement dosage (mass fraction) had a great influence on the age at which an intact core could be taken out. When the cement dosage was 5.5%, intact cores could be taken out from specimens of all three gradation types in seven days; when the cement dosage was 4.5%, intact cores could be taken out from specimens with suspend-dense structure grading until 14 days; as the cement dosage dropped to 3.5%, intact cores were failed to be taken out under the three gradation types in seven days. When the gradation tended to suspend-dense structure, the side walls of cores were less dense. Intact dense cores could be taken out in seven days, only when the cement dosage was above 5.5% under suspend-dense structure grading, otherwise the curing age must be increased. Whether the intact cores of CTAB could be taken out was closely related to splitting strength, when the splitting strength reached the coring critical strength, intact dense cores could be taken out. There was a hyperbolic relationship between the splitting strength of CTAB and the maturity curve under different curing paths. Based on the coring critical splitting strength and the relationship between splitting strength and maturity, the critical maturity standard of coring was put forward. It is feasible to use coring critical maturity to scientifically determine the integrity quality evaluation time of CTAB.