Abstract: Mucopolysaccharidosis（MPS） is a genetic metabolic disease. The inactivation of α-L-iduronidas（IDUA）encoded by human IDUA gene is the main cause of typeⅠMPS. The aim of this paper was to construct a CRISPR/Cas9 editing system that specifically targets the Idua gene of the mouse, to simulate the mutation of the human IDUA gene, and to provide an efficient gene editing system for the establishment of cell models and animal models that accurately simulate typeⅠMPS. This study screened human IDUA genes for pathogenic mutation, and mapped candidate mutation site on mouse Idua genes as desired mutation sites. Then, the steps of sg RNA design,expression plasmid construction, transfection, drug screening, and TA cloning and sequencing were performed.Results proved that the designed sg RNA has high efficiency and validation in Idua targeting. The pathogenesis and the treatment of MPS are of great significance. This study laid a foundation for the establishment of type ⅠMPS cell model and MPS animal model, and was of great significance for further studying the pathogenesis of MPS and exploring the treatment of MPS.