<p>The use of literal prompts (LPs) and inferential prompts (IPs) in shared book reading (SBR) facilitates children’s use of language and promotes their thinking and understanding about the stories discussed and beyond. Furthermore, SBR provides a platform for mildly autistic children to have multiple rounds of communication with educators. This study investigated the contribution of LPs and IPs on the language development and affective factors of language learning in mildly autistic children. This study included 187 mildly autistic Chinese children who were stratified by random sampling and assigned into three groups (LP, IP and control). The mildly autistic children’s language skills were tested immediately before and after the 12-week SBR intervention. Their parents were also included in this study. The results indicated that using prompts had positive effects on the mildly autistic children’s language skills and on the affective factors central to language development. Moreover, LPs were beneficial in fostering mildly autistic children’s affective factor development, whilst IPs fostered their Chinese word reading and listening comprehension skills. These findings indicated the benefits of using prompts during parent–child SBR, along with the extent to which prompts contribute to different language skills and affective factors central to language development in mildly autistic children.</p>