A method for the biological treatment of organic waste containing impurities consisting of non-biodegradable materials, including: • a first step of wet mechanical separation of the non-biodegradable materials present in the abovementioned organic waste in order to obtain a purified organic fraction, • a second step of dehydrating the purified organic fraction in order to obtain a dehydrated purified organic fraction and an effluent, • a third step of dry anaerobic biological treatment of the dehydrated organic fraction in order to obtain organic residues.