The peach fruit moth (PFM), Carposina sasakii Matsumura, is a major phytophagous orchard pest widely distributed across Northeast Asia. Here, we report the chromosome-level genome for the PFM, representing the first genome for the family Carposinidae, from the lepidopteran superfamily Copromorphoidea. The genome was assembled into 404.83 Mb sequences using PacBio long-read and Illumina short-read sequences, including 275 contigs, with a contig N50 length of 2.62 Mb. All contigs were assembled into 32 linkage groups assisted by the Hi-C technique, including 30 autosomes, a female-specific W chromosome and a Z chromosome. BUSCO analysis showed that 98.2% genes were complete and 0.4% of genes were fragmented, while 1.4% of genes were missing in the assembled genome. In total, 23,218 protein-coding genes were predicted, of which 82.72% were functionally annotated. Because of the importance of diapause triggered by photoperiod in PFM, five circadian genes in the PFM as well as in the other related species were annotated, and potential genes related to diapause and photoperiodic reaction were also identified from transcriptome sequencing. In addition, manual annotation of detoxification gene families was undertaken and showed a higher number of ABC and GST genes in PFM than in most other lepidopterans, in contrast to a lower number of UGT genes, suggesting different detoxication pathways in this moth. The high-quality genome provides a resource for comparative evolutionary studies of this moth and its relatives within the context of radiations across Lepidoptera.