Aiming at the measurement of γ radioactive contamination on the surface of object, a method of joint alarm and contamination area division based on the adjacent position relationship of detectors is proposed. The detection sensitivity is improved by making full use of the relevance of the relevant information and the joint detection algorithm by using the detection data when measuring the object, including the measurement count, the adjacent position relationship of the detector and other information; and the polluted area is analyzed according to the position relationship of the alarm detector area, and the polluted area is displayed.The results show that the method makes the pollution display more intuitive and the decontamination more targeted.