We use CRISPR/Cas9 gene editing technology to knock lncRNA SOX21-AS1 into the “safe harbor” AAVS1 site, and then use RT-qPCR and WB to detect the expression level of related genes, and use the CCK-8 method to detect the proliferation of osteosarcoma. The gene discussed is SOX21; the disease is osteosarcoma.