The identification and analysis of sex pheromone synthase genes in Illiberis pruni provided a theoretical basis for exploring the molecular mechanisms of sex pheromone synthesis. Based on transcriptome data from the abdomens of both sexes and female wings of I. pruni, sex pheromone synthase genes were screened and identified followed by bioinformatics analysis. Real-time fluorescence quantitative PCR was used to analyze the expression patterns of these genes in different tissues of male and female adults. A total of 21 sex pheromone synthase genes were identified (3 Dess, 2 FARs, 1 FAS, 10 ACTs, 3 ACCs and 2 ARs), and bioinformatics analysis revealed that these genes had significant variation in protein molecular weight, suggesting that they were unstable proteins. Subcellular localization analysis showed that the corresponding proteins were mainly located in the cytoplasm and mitochondria. Based on the phylogenetic tree results, it was inferred that the ACCs genes and ACTs genes of I. pruni were closely related to the sex pheromone-related genes of Streltzoviella insularis and Danaus plexippus. RT-qPCR analysis demonstrated that 16 genes exhibited female-biased expression in the wings, 7 genes were highly expressed in the female abdomen, and 2 genes showed male-biased expression in the male thorax. These research findings provided a foundation for the functional study of sex pheromone-related genes in I. pruni.