A method and device for harmless treatment and recycling of waste refrigerators. Plastic parts, electrical boxes, compressors, and condensers are disassembled at a disassembling station. Refrigerants from compressors are recycled at a fluoride-extracting station. Refrigerator bodies and doors are transferred to a double shaft shredder and a rolling crusher for crushing. Crushed materials are sorted out by wind force, by a self-discharge type iron remover made of permanent magnet and a cylindrical iron remover for magnetic separation. The device is placed in an enclosed workshop equipped with a multistage ventilation system, a protective device of nitrogen, a device for spraying, dedusting, and cooling, and an on-line detection and alarm control device for cyclopentane gas concentration, polyurethane dust concentration, and temperature. The method and device have low manufacturing and operating costs and are dustproof, explosion proof, environmentally friendly and has excellent recycling effects.