The invention discloses a method for screening a CHO cell line high-expression site. The method comprises the following steps: integrating slow virus with a green fluorescence gene into a CHO cell genome, collecting monoclonal cells with high fluorescence expression quantity by a flow sorting method, performing expanding culture, and then screening out a corresponding high-expression integration site by using a chromosome walking technology. According to the method, a CRISPR/Cas9-mediated site-specific integration technology is combined, a to be expressed foreign gene can be quickly and accurately into a found site, and a foreign protein high-expression cell line can be quickly and efficiently obtained.