The invention discloses a CRISPR-Cas9 for targeting knockout of a human intestinal cancer cell CNR1 gene, and specific sgRNA sequences thereof. Firstly, an sgRNA specifically targeting CNR1 gene second exon is obtained, and base sequences of the sgRNA are as shown in SEQ ID NO. 1; secondly, the sgRNA of the CNR1 gene is constructed to a lentiviral vector system, and the lentiviral vector system contains Cas9 protein; and finally, a CRISPR/Cas9 lentivirus containing the sgRNA is infected with human intestinal cancer HT-29 cells, and a cell strain with CNR1 protein expression level significantlybeing reduced is obtained. The operation steps are simple, good sgRNA targeting is achieved, and the cutting efficiency to the CNR1 gene is high; and in addition, the constructed CRISPR/Cas9 lentiviral system has the advantage of high knockout efficiency, and can specifically knock out the CNR1 gene, human intestinal cancer cells with the CNR1 gene being knocked out is obtained, and therefore a powerful tool for further study of the mechanism of action of CNR1 in intestinal cancer cells is provided.