Children with autism spectrum disorder (ASD) have deficits in audiovisual speech perception and temporal processing. The current study has examined the relationship between the audiovisual speech perception deficits and temporal processing deficits in children with and without ASD. To this end, using the McGurk paradigm, we implemented two experiments to explore audiovisual speech perception (Experiment 1) and temporal processing (Experiment 2), as well as the correlation between them, in children with ASD and typically developing (TD) children. We recruited 4- to 8-year-old children, some with ASD and some TD, to perform a McGurk task in Experiment 1 (24 children with ASD, 26 TD children) and to complete a simultaneity judgement task in Experiment 2 (31 children with ASD, 29 TD children). On the basis of the data from participants who participated in both Experiment 1 and Experiment 2 (20 children with ASD, 21 TD children), we analyzed the correlation between audiovisual speech perception and temporal processing in children with ASD and TD children separately. We found that children with ASD showed weaker audiovisual speech perception (based on the population) and less acute temporal processing compared with TD children. The correlation analysis revealed that audiovisual speech perception and temporal processing were correlated in TD children when the visual led the audio but not when the audio led the visual. No such correlation was found in children with ASD either when the visual led the audio or when the audio led the visual. The present study implicated that the correlation between audiovisual speech perception and temporal processing might be contingent on the range of individual temporal processing abilities.