[Objectives]  CRISPR/Cas9 is a novel genome-editing tool that has recently had broad application in many fields of research. CRISPR/Cas9 has the advantages of simplicity, efficiency and high specificity. BmSuc1 encodes β-fructofuranosidase (β-FFase, a fructosyl-hydrolytic sucrase) in the silkworm Bombyx mori (Lepidoptera). BmSuc1 is also the first β-FFase gene to have been cloned and identified in an animal. The physiological function of BmSUC1 in the silkworm is probably related to defense against mulberry alkaloids. However, further research is needed to confirm this. In order to clarify the role of BmSUC1 we used the CRISPR/Cas9 genome-editing system to construct a dual-sgRNA expressing vector. [Methods]  We first designed two sgRNAs against BmSuc1 ORF and inserted these into the Sal I and Nhe I restriction enzyme sites of a CRISPER edition vector using the homologous recombination method. We then microinjected the recombinant CRISPR plasmid into G₀ silkworm eggs and created a G₁ generation by G₀ sib-crossing. [Results]  Both sgRNA insertions were verified by polymerase chain reaction and sequencing. DsRed2 fluorescence confirmed that we successfully obtained positive transgenic G₁ individuals. [Conclusion]  This study provides a detailed description of the construction of a CRISPR edition vector to express dual sgRNAs. The resultant positive transgenic silkworms will help clarify the biological role of BmSuc1-coding β-FFase in the silkworm.