Gelechioidea represents the most diverse superfamily of tiny boring pests in Lepidoptera that pose a serious threat to agricultural and forestry economic crops. However, the lack of high-quality genome of highly specialized species makes it difficult to draw general conclusions about the mechanism of the close binding relationship between pests and crops. In this study, based on second- and third-generation sequencing reads, we constructed a chromosome-level genome for the Atrijuglans aristata, a specialized boring pest, that specifically harms the green husk of cultivated walnuts. The genome is 480.99 Mb and spans 31 pseudo-chromosomes, including Z and a portion of W chromosome. Contig N50 and scaffold N50 of the genome are 2.68 Mb and 16.01 Mb respectively. The BUSCO completeness achieves 95.6% with a total of 22,542 protein-coding genes are annotated. As the first sequenced genome of Stathmopodidae family, this high-quality genome provides a genetic basis for the mining of genes for important functional traits in A. aristata, as well as an important reference for the study of host adaptation of the (insect) specialists.