Abstract: This paper investigated the effect of different heating styles（heating by electricity or solar energy） and evaporation conditions on the concentration of anaerobic digestion effluent,and the influence of different factors on the concentration of anaerobic digestion effluent was compared. The results showed that the evaporation rate of the anaerobic digestion effluent and the concentration effect of TP and TK were increased while the retention rate and concentration of NH3-N and TN were gradually decreased with the increasing of vacuum degree,initial pH value or heating temperature. The optimum heating temperature,vacuum degree and initial pH value of anaerobic digestion effluent concentration system was respectively 85 ℃,90% and 5.0 via comprehensive consideration of the multiple of volume reduction,the nutrient concentration effect and the nutrient retention rate. Then the concentration of anaerobic digestion effluent via solar heating was conducted under the conditions of vacuum degree of 90% and initial pH value of 5. The results indicated that there was about 1 to 1.5 h when 500 m L of anaerobic digestion effluent being concentrated to 50 mL,and the main nutrients of nitrogen,phosphorus and potassium of the concentrated anaerobic digestion effluent were improved almost 10 times with the nutrient retention rate of 90%. The total nutrient content of N,P and K in the concentrated anaerobic digestion effluent was close to the requirement of the Standard of Liquid Fertilizer DB33/699—2008"Quality and Safety Requirements for Organic Liquid Fertilizer".Obviously,the concentration of anaerobic digestion effluent by negative evaporation system via solar heating is feasible,and it could provide a new way for the utilization of anaerobic digestion effluent.