Effect of aging conditions on the hydration and setting performance of cement paste with the addition of TEA were investigated through the combined techniques of calorimetry, Vicat test, XRD and TGA. It is found that, along with the increased aging time and RH, an obvious formation of AFt, AFm and CH can be found due to the pre-hydration of clinker. Besides, under the RH of 90%, the pre-hydration within the first day was significantly improved, and this process was continuously developed in the next 7 days through the strong carbonation of CH. Further analysis indicates that the pre-hydration can retard the cement hydration and increase the setting time of cement paste. Compared to the reference, a prolonged induction period and an increased setting time were observed for the aged samples with the addition of TEA. Besides, the commonly observed flash setting performance under the TEA dosage of 0.5 wt.-% was eliminated when the samples were pre-hydrated under 90% RH, which indicates the pre-hydration can alleviate the strongly accelerated aluminate phase hydration caused by TEA.