Abstract: 【Objective】 A local variety called Xinjiang old man melon was used as the research material. The entire leaf gene of Xinjiang melon was edited and the knockout vector of CRISPR / Cas9 of Xinjiang melon entire leaf gene constructed. After that, the the maximum tolerance to hygromycin in the muskmelons was analyzed in the hope of laying a foundation for the study of the function of muskmelon cleavage gene in Xinjiang. 【Method】Based on the previous study of entire leaf gene PLL in the melon and melon genomic data, the specific target site of exon of PLL gene was designed, and the CRISPR/Cas9 knockout vector of melon entire leaf gene PLL was constructed Then, the vector was transformed into Escherichia coli and sequenced and the tolerance of melon to hygromycin analyzed.【Result】A 20 bp target site was selected for the exon of the whole leaf gene PLL, and the sgRNA frame was designed according to the target site, and attached it to the CRISPR/Cas9 knockout vector, then the vector was successfully transformed into Escherichia coli. Melons could tolerate the maximum concentration of hygromycin at 10 mg/L.【Conclusion】The knockout vector of melon entire leaf gene PLL was successfully constructed and transformed into Escherichia coli, which analyzed the maximum concentration of cantaloupe tolerance to hygromycin. This has laid a foundation for further study on the function of PLL gene in muskmelon leaves of Xinjiang by using CRISPR/Cas9 gene editing technique.