The Blaps rhynchopetera Fairmaire is a significant medicinal resource in southwestern China. We utilized Nanopore and Hi-C technologies in combination to generate a high-quality, chromosome-level assembly of the B. rhynchopetera genome and described its genetic features. Genome surveys revealed that B. rhynchopetera is a highly heterozygous species. The assembled genome was 379.24Mb in size, of which 96.03% was assigned to 20 pseudochromosomes. A total of 212.93Mb of repeat sequences were annotated and 26,824 protein-coding genes and 837 non-coding RNAs were identified. Phylogenetic analysis indicated that the divergence of the ancestors of B. rhynchopetera and its closely related species Tenebrio molitor at about 85.6 mya. The co-linearity analysis showed that some chromosomes of B. rhynchopetera may have happen fission events and it has a good synteny relationship with Tribolium castaneum. Furthermore, in the enrichment analyses, the gene families related to detoxification and immunity of B. rhynchopetera facilitated the understanding its environmental adaptations, which will serve as a valuable research resource for pest control strategies and conservation efforts of beneficial insects. This high-quality reference genome will also contribute to the conservation of insect species diversity and genetic resources.