Abstract: When INCO method is used to treat cyanidation tailings pulp in gold mines,generally,conventional open aeration tank reactor is adopted,leading to poor effect of aeration dispersion,low utilization rate of oxygen,and secondary pollution to environment.In light of that,the conventional open aeration tank reactor is optimized into cyclone microfoam aeration reactor,adding functions to the reactor for  cyanidation tailings pulp such as pH adjustment,reagent addition and mixing,cyclone microfoam aeration and negative pressure gas absorption.With the optimized reactor,power consumption is saved by 30 %,oxygen utilization rate is improved by 25 %,the cyanidation tailings pulp can be treated in an efficient,safe and environmental way.