Abstract: A full air-exchanging safety cabinet is provided, comprising a cabinet body having an accommodating space, an air inlet, an air vent and an experiment operation entrance, an air-feeding blower provided at the air inlet side of the cabinet body, a first air filter for filtering air introduced by the air-feeding blower, an experiment operation zone located under the cabinet body and provided with a working platform, a plurality of slits disposed at opposite sides of the experiment operation zone, a glass plate provided at an outer side of the experiment operation entrance of the cabinet body, a second air filter provided at an upper portion of the cabinet body, a speed and pressure monitoring device located at the air vent side of the cabinet body and connected to the second air filter, and an exhaust system connected to the speed and pressure monitoring device.