Abstract: Aiming at the problem that the phosphorus screen of the electron backscatter diffraction detector was close to the sample and was easy to hit the screen in operation, the risk points of the electron backscatter diffraction technology and two anti-collision alarm functions were analyzed. The influence of screen impact on detector was discussed, and the precautions during the placement of the sample were summarized. The limitations of the anti-collision functions were analyzed. The results show that in addition to the lack of understanding of the risk, the two accidents were caused by the improper use of software functions, which caused the sample table to move greatly and quickly. Combing operational risk, more careful operation and more standardized management could avoid the recurrence of such problems.