Abstract: Micro-relay is widely used in aerospace, weapons, ships and other engineering fields. Particularity of working environment requires it to have excellent contact behaviors. The reed structure of this kind of relay will deform when it moves, and the traditional dynamic analysis method of contact system based on rigid body assumption is obviously unable to meet the calculation requirements and analysis accuracy. Therefore, taking a micro-relay as an example, a rigid-flexible coupling impact dynamics and bouncing analysis method was proposed based on the coupling of rigid body motion, flexible deformation and structural collision process of movable parts. The reed is equivalent to a cantilever beam structure. Based on the differential equations of the electricity, magnetism, force and displacement of the reed, the contact bounce dynamic model of the relay was established. The forces of the reed before and after deformation were analyzed, and contact-separation-contact dynamic properties of the closed reed were studied. The contact bounce changes of the relay under different contact gaps, connecting rod positions and control voltages were calculated in detail. The accuracy of the proposed model was verified by experiment. It is found that the interaction between elastic deformation and collision process of the reed is the important reason for the unstable contact of the relay. In addition, appropriately reducing the contact gap, shortening the push distance between the connecting rod and the contact point can effectively improve the contact performance of the micro-relay.