The invention discloses a fast 
CRISPR-Cas9 working efficiency testing 
system and application thereof. The testing 
system comprises a 
plasmid used for expressing sg 
RNA, a 
plasmid used for expressing Cas9 and a 
reporting system used for testing the 
CRISPR-Cas9 
gene editing efficiency; the 
reporting system can splice the C-terminal of a 
nucleotide segment capable of coding effective 
protein and the N-terminal of a 
reporter gene and insert two restriction 
endonuclease enzyme digestion sites into the splicing position; before a special 
gene is edited (knocked out) through the 
CRISPR-Cas9 
system, selection of a target sequence is vital, and the selection can influence the recognition efficiency of the sg 
RNA to target 
DNA, the 
binding efficiency of the sg 
RNA with the target 
DNA, the targeted 
cutting efficiency of the Cas9 and the NHEJ repairing efficiency. According to the system, the 
gene editing efficiency of different sgRNA-target 
DNA sequences can be quantitatively compared, the sgRNA with the best working effect can be determined within a short time, the actual knockout success rate is increased, therefore, the working cost can be lowered, the working efficiency can be improved, and the working progress can be promoted.