Audiovisual temporal integration ability, reflected by the size of the temporal binding window (TBW), plays an important role in reading. The audiovisual TBW is not fixed, but dynamically changes during the integration process, this is referred to as rapid temporal recalibration. To investigate the rapid audiovisual temporal recalibration ability across age and its correlation with reading, the present study conducted simultaneity judgment (the index includes ΔPSS and ΔTBW) tasks involving speech (Experiment 1; children: Mage = 10.70, adults: Mage = 24.52) and non-speech (Experiment 2; children: Mage = 10.19, adults: Mage = 24.26) audiovisual stimuli in native Mandarin-Chinese-speaking child and adult groups (n = 36 in each group). Results showed that children’s ΔPSS and ΔTBW for speech stimuli were comparable to those of adults. However, when examining trial-by-trial changes in TBW during the integration process, a gap between children and adults was evident. Besides, for non-speech stimuli, children significantly differed from adults in both ΔPSS indicators and the integration process. Moreover, for both children and adults, the correlation and regression analysis showed that the rapid audiovisual temporal recalibration ability of both speech and non-speech stimuli explained reading fluency uniquely after controlling TBW, age, and gender.