The invention discloses a non-auxiliary material sludge composting method. The method provided by the invention is composed of the following steps: cultivating indigenous microorganisms which are extracted from compost sludge at different temperatures, obtaining a leavening agent special for sludge compost, inoculating the microorganisms into sludge at corresponding temperature sections for adapting microorganisms in the leavening agent to the environment of compost sludge in a short period of time, rapidly breeding the microorganisms, thereby rapidly starting the compost, and rapidly decomposing the compost body with stable quality of the compost product, and realizing non-auxiliary material sludge composting. The non-auxiliary material sludge composting method has the advantages of long continuous time of high temperature, and harmless treatment of the compost. The composting method does not need auxiliary materials and simplifies the composting technology, and saves the composting cost, and the composting production environment is cleaner.