Objective: To optimize desalination process of ethanol supernate of Mactra veneriformis

and analyze its changes in chemical composition and safety. Method: Taking desalination rate

transfer rates of solid content and amino acids(in the amount of taurine and alanine) as comprehensive evaluation index

orthogonal test was adopted to optimize desalination process with the concentration of sample solution

pH of liquid and desalination time as factors.Composition changes of ethanol supernate of M. veneriformis before and after desalination was compared

and its safety was evaluated by acute toxicity test. Result: The best desalination process was as follows:sample solution concentration of 34 g · L-1

pH of 4-5 and desalination time of 1.5 h.With optimum process for desalinating

desalination rate was over 90%

transfer rate of solid content was more than 65%

retention rates of taurine and alanine were more than 90%.Lethal dose (LD50) of ethanol supernate before desalination was 27.18 g · kg-1

while after desalination with electrodialysis

the maximum tolerated dose increased to 37.48 g · kg-1. Conclusion: Toxic ingredients in ethanol supernate of M. veneriformis after desalination reduce significantly

but at the same time

effective components still remain and safety has improved significantly.Optimized desalination process is stable and feasible

it can provide theoretical basis for further research and development of M. veneriformis.