[Objectives]  By comparing the gut transcriptome of Streltzoviella insularis Staudinger larvae feeding on different hosts, the aim is to explore the genes related to the host adaptation of S. insularis larvae. It will provide molecular biological data for exploring the adaptation mechanism of S. insularis larvae to the host. [Methods]  The Illumina second-generation sequencing technology was used to determine the transcriptome of the S. insularis gut, after the larvae were fed on three different hosts (Fraxinus pennsylvanica, Ginkgo biloba, Sophora japonica) 15 days. BLAST software were performed GO and KEGG enrichment on unigene sequences. The genes related to host adaptation of larvae were screened by comparative analysis. [Results]  There were 916 differentially expressed genes between the larvae feeding on S. japonica and the larvae feeding on F. pennsylvanica, 1 163 differentially expressed genes between the larvae feeding on G. biloba and the larvae feeding on F. pennsylvanica, and 1 621 differentially expressed genes between the larvae feeding on G. biloba and the larvae feeding on S. japonica. The up-regulated differential genes were closely related to detoxification metabolism, hydrolase and transporter proteins. The number of differentially expressed genes annotated to detoxification enzymes (17 genes) and digestive enzymes (20 genes) was significantly higher than those to protective enzymes (5 genes) in larvae fed on different hosts. Two detoxification enzymes genes, three digestive enzyme genes and a protective enzyme gene were screened out as the key genes for the study of S. insularis larval adaptation to hosts. [Conclusion]  This study initially revealed the differentially expressed genes of S. insularis larvae in response to different hosts. It will provide a basis for further exploration of the adaptation mechanism of S. insularis larvae to hosts.