The invention discloses a preparation method of a 
cell strain capable of expressing 
glucocerebrosidase with 
high mannose content. The preparation method comprises the following steps: (1) carrying outlipofection 
transfection, namely, aiming at the sequence of a GNT1 
gene, designing a sgRNA sequence guiding 
cutting of 
endonuclease, recombining the sgRNA sequence into a knock-out vector, thus obtaining synthetic plasmids with coexpression of sgRNA and 
endonuclease, and transfecting a 
cell pool stably expressing 
glucocerebrosidase by adopting the synthetic plasmids through a 
liposome transfection method; (2) carrying out 
cloning by adopting a 
limiting dilution method, namely, screening out 
monoclonal cells, and carrying out enlarged culturing; (3) carrying out 
mutation cloning screening on the 
target gene, namely, acquiring monoclone with the GNT1 
gene knocked out through 
cell PCR sequencing, and thus the 
cell strain capable of expressing 
glucocerebrosidase with 
high mannose content is obtained. The 
cell strain can stably express glucocerebrosidase, meanwhile, the content of the 
mannose is obviously improved, the binding capacity with 
mannose receptor is effectively improved, the 
enzyme activity capacity is improved, and the purpose of increasing the efficacies is achieved.