The invention relates to a recombinant human 
nerve growth factor purifying method based on a CHO 
cell expression 
system. The recombinant human 
nerve growth factor purifying method based on the CHO 
cell expression 
system comprises the following steps: 1), centrifugating supernatant, successively removing living cells and 
cell fragments, and removing impurities and 
bacteria by filtering; 2), applying a supernatant sample to an EMD SO3-(M) 
chromatography column, rinsing unbound 
protein and impure 
protein, eluting and collecting a 
target protein peak; 3), concentrating the 
protein with 
ultrafiltration equipment with a molecular weight cutoff of 3K; and 4), applying the sample to Superdex 75-containing 
chromatography column and collecting the 
target protein peak, namely a recombinant human 
nerve growth factor stoste. According to the CHO cell expression 
system and the recombinant human nerve 
growth factor purifying method based on the CHO cell expression system, the recombinant human nerve 
growth factor with the purity greater than 98% and the 
specific activity higher than the 5* 10 to the power of 5 AU / mg can be prepared; compared with other methods, the recombinant human nerve 
growth factor purifying method based on the CHO cell expression system has the advantages that the steps are reduced, the 
production cycle is greatly shortened, and the 
processing capacity and the yield are improved; therefore, the recombinant human nerve growth factor purifying method based on the CHO cell expression system is application for large-scale production.