Small electromagnetic relay having test button capable of realizing state locking

Provided is a small electromagnetic relay having a test button capable of realizing state locking. The inside of a housing of the small electromagnetic relay is provided with an electromagnetic system and a contact system and is further provided with a space for accommodating a test button and allowing a spring thereof to operate. The button is fixedly installed in a button seat on the housing and comprises a shaft rod, a button head and a driving head, wherein the outer surface of the shaft rod is provided with a locking bump, the button head is arranged in the upper part of the shaft rod, and the driving head is arranged at the bottom of the shaft rod. A positioning shoulder is formed in the upper part of the driving head. An action input part of the contact system and the driving head on the button work in a cooperative way. The button seat is provided with a shaft hole and a locking groove communicated with the shaft hole, and the bottom of the button seat is provided with a positioning surface. Two ends