The invention discloses a method for reduction and detoxification of hazardous waste sludge. The method comprises the steps: adding a microbial bacterial agent to the sludge, adding an auxiliary material for conditioning, providing an external heating source, performing continuous stirring, and performing aeration, wherein the sludge is chemical hazardous waste sludge with a water content of 80% or above, the water content is 70% after the auxiliary material is added, and the microbial bacterial agent is complex bacteria. According to the method, bio-thermal energy generated through degradation of organic matter in the microorganism high-temperature process and the complex bacteria are utilized to decompose the organic matter, destroy the aggregate structure and disperse the sludge particles, the interstitial moisture and surface moisture are turned into free water, the binding force is weakened, and the removal difficulty is reduced; and in addition to the auxiliary heat, the temperature inside a box body is kept at 60-80 DEG C. According to the method, the optimal control conditions in the process of reduction and detoxification are determined, the method has the advantages of ahigh degree of reduction, high detoxification efficiency, low treatment cost, a high comprehensive utilization rate, no secondary pollution, simple operation and the like, and the economy benefits, environmental benefits and social benefits are good.