Method for improving efficiency of CRISPR mediated homologous recombination

The invention discloses a method for improving the efficiency of CRISPR mediated homologous recombination. The method includes the steps of: inhibiting the expression of Lig4, DNA-PK and XRCC6 by shRNA so as to inhibit the non-homologous end joining (NHEJ) repair pathway; conducting fusion expression on sgRNA and shRNA at targeting genome specific positions to form shRNA-sgRNA polycistron; and placing the polycistron at the RNA polymerase II or RNA polymerase III promoter downstream. The carrier constructed by the method provided by the invention has a concise structure and is convenient to use, also enhances the homologous recombination efficiency by dozens of times, greatly expands the function and application of the CRISPR carrier, and is a good tool for functional gene and signal pathway research, medical research, and recombinant protein expression.