Abstract: Study on debittering process of membrane separation technology on Pleurotus eryngii hydrolysates.On the basis of the single-factor test, using response surface optimization, get the optimal conditions of the 500u nanofiltration membrane separation debittering:pressure 0.67MPa, pH7.81, temperature 45.0℃.In the debittering filtrate, transmittance of the amino nitrogen was 82.6% and the bitter score was 1.8.Analysis of the basic nutrition content in the enzymatic solution and debittering filtrate were investigated, in the latter the amino acids, guanosine monophosphate and inosine monophosphate retention rates were 82.6%, 79.9% and 75.2%, respectively.The results showed that in the enzymatic solution, amino acids and nucleotide retention were higher, the effect of was debittering was good and the membrane separation technology could be applied to the protein enzyme solution to take off the bitter.