For overcoming a problem of no contact conduction of an existing relay when conduction is required or relay failure caused by adhesion when contact separation is required, the invention provides a relay which comprises an insulating cover, two static contact bridges, a dynamic contact bridge, a driving shaft and a driving structure. The inner surface of top of the insulating cover is provided with two step parts. The lower surface of each step part is provided with a conductive layer. The two conductive layer are isolated from each other. The relay further comprises an auxiliary conduction structure and an auxiliary testing structure. The auxiliary conduction structure comprises a conductive member and an elastic member. The conductive member is arranged on the driving shaft. The driving shaft upwards moves and drives the dynamic contact bridge to be conducted with the static contact bridge, and furthermore the conductive member contacts with and is conducted with the two conductive layers. The driving shaft downwards moves and drives the dynamic contact bridge to be separated from the static contact bridge, and furthermore the conductive member separates the two conductive layers. The auxiliary testing structure comprises two auxiliary terminals. The two auxiliary terminals are electrically connected with the two conductive layers. The relay according to the invention can quickly test the fault above through connecting the auxiliary testing structure with an external auxiliary testing line.