A safety cap assembly of power battery comprises a cap plate and a first terminal unit, a second terminal unit, a vent, an electrolyte-injection hole and a safety reverse valve provided to the cap plate; the first terminal unit is electrically connected to the cap plate; the second terminal unit is insulated from and assembled to the cap plate; the safety reverse valve is electrically connected to the cap plate; a short circuit protection conducting plate is provided above the cap plate, is electrically connected to the second terminal unit, and is positioned above the safety reverse valve; the first terminal unit comprises a first terminal body, and a metal gasket and a resistance plate around the first terminal body, the resistance plate is provided below the metal gasket and comprises a substrate and a coating on a surface of the substrate.