The refinery residual sludge reduction using multi-function microbe,which consists of mixed yeast strains,photosynthetic bacteria and mixed bacteria was studied. After a period of research time,the excess sludge reduction experiment shows that function microbe was improved the reduced effect of excess sludge significantly.The results show that compared with blank test,MLSS removed rate of the sludge are increased by 13.81% for mixed yeast strains,by 30.58% for mixed photosynthetic strains and by 37.94% for mixed microflora.Sedimentation performance of excess sludge is improved after the activity of the multi-function microbe.The pH value is all gradually reduced.The effect of multi-function microbe degeneration changed the component of petroleum obviously.It strengthened the degeneration degree of normal hydrocarbons that have low and moderate carbon.The multi-function microbe environment is favorable to degenerate the high-carbon hydrocarbons into the low-carbon hydrocarbons.