The invention discloses a method for detecting the pollution toxicity of soil by adopting electric signals of a double-chamber microbial fuel cell and belongs to the technical field of detection of soil pollution. According to the method, electric quantity generated by decomposing organic matters through soil microorganisms is used as an index for detecting the pollution toxicity of the soil; compared with a traditional method for detecting the toxicity by microorganism activity, biomass and the like, the method has the advantages of low cost, easiness in operation and short detection period. The double-chamber microbial fuel cell used in the method comprises an anode, a cathode, an anode fixing groove, a cathode fixing groove, an anode chamber, a cathode chamber, a top cover of the anode chamber, a top cover of the cathode chamber, a diaphragm, a rubber cushion, a lead wire, a load, bolts and nuts. Before the double-chamber microbial fuel cell is operated, polluted soil and glucose are mixed and are added into the anode chamber; a potassium ferricyanide solution is introduced into the cathode chamber to be used as an electron acceptor; after the double-chamber microbial fuel cell is operated for 48 hours, the generated electric quantity in the 48 hours is calculated and is used for evaluating the toxicity of pollutants. The method for detecting the pollution toxicity of the soil by adopting the electric signals of the double-chamber microbial fuel cell has high scientific values and application values.