In order to study the  effects of current density on the  purification efficiency of the aquaculture wastewater treatment by
electrochemical technology, an experiment was carried out. In this experiment, the effects of four groups of different current densities (2,4,8 and 12 mA/cm2) on nitrogen removal, trichloromethane and current efficiency were investigated, on the basis of which, the generated  by-products and energy consumption were analyzed. The results showed that the removal efficiency of pollutants were obviously accelerated with the rising of current density. With the increase of current density, the removal rate of ammonia nitrogen increased from 46.9% to 97.8%, the removal rate of nitrates increased from 32% to 95.5%, and the COD removal rate increased from 25.7% to 73.1%. The free chlorine generated in electrolysis and the increased oxidation reduction potential played an important role in disinfection of wastewater. Complete sterilization could be achieved after  reacting for 40 minutes under each group of current density. As the free chlorine in water gradually decreased after electrolysis, the number of bacteria began to  exponentially grow. Current efficiency declined from 33.3% to 15.5% as the current density improved from 2 to 12 mA/cm2, which also caused the increasing of water treatment cost. The experiment showed that electrochemical technology has a good effect in treating aquaculture wastewater, and propriate current density has great significance for improving the efficiency of nitrogen removal and reducing energy consumption.