Abstract: The mixer is an important device of the microwave system. A mixer is damaged in the vibration test, so it is necessary to analyze the damage mechanism and find improvement methods. Because the mixer is too small to be tested, it is necessary to analyze the failure reason by mechanical simulation. Compared with general structures, the key of the mechanical simulation of this mixer is the equivalent modeling of the internal micro components. The analysis indicates that the cause of the damage is that the internal magnetic ring is not fixed, and the excessive displacement in vibration causes the excessive stress on the connecting wire, which leads to the damage of the wire. This conclusion not only can guide the subsequent improvement of the mixer, but also provides the deformation characteristics and the sensitive frequency range of such microwave devices under vibration condition, which can be used as a reference to solve similar problems.