In order to maximize the detection efficiency of the surface contamination detector on α rays and make up for the problems of insufficient protective measures of the detector,a new detection window protection device for wound contamination detector was designed.The device was consisted of a protective film and a fixed frame sleeve.The protective film was made of a transparent flat Mylar film with a thickness of≤2.5 μm and a circular shape.Its diameter matched the detection surface diameter of the wound radiation measuring instrument probe and can be used in combination with the appropriate model of wound radiation measuring instrument probe.The sleeve was provided with a closed end and an open end,the protective film was fixed on the inner side of the closed end of the sleeve,and the open end of the sleeve was provided with an annular fixing buckle,so that the sleeve can be firmly installed on the probe of the disposable wound radiation measuring instrument.After installation,the protective film can be closely attached to the detection surface of the probe of the wound radiation measuring instrument.Two commonly used contamination detectors were selected to measure the artificial radioactive sources under three protection conditions:film-free protection,plastic wrap protection and new protective devices,and the detection efficiency and operability of the detection window protection device of the new wound contamination detector were tested.The results showed that compared with the traditional protective measures of plastic wrap,the new device can significantly improve the detection efficiency of wound radioactive contamination,especially α contamination,and effectively protect the instrument and equipment,and improve the detection efficiency of wound pollution operators.