This article describes the development of the nuclear industry at home and abroad, and introduces the sources and types of radioactive pollutants from nuclear facilities decommissioned. The focus is on the decontamination methods in nuclear decommissioning technology, mainly mechanical and physical decontamination methods, chemical decontamination methods, electrochemical decontamination methods and biological decontamination methods. The mechanical physical decontamination method mainly includes smelting decontamination, laser decontamination, mechanical decontamination, ultrasonic decontamination and high-pressure water cleaning decontamination technology. Chemical decontamination methods mainly include foam method, gel method, oxidation-reduction method, and complexation method. The current research status of these methods at home and abroad is also explained. A reasonable and effective combination of these decontamination methods has become the main direction for the development and application of decontamination technologies for decommissioning nuclear facilities in the future.