The design of an experimental apparatus and its teaching mode are proposed for simultaneously visualizing the flow and the spray of gaseous fire suppressants, whose flow is complex and invisible. With electrical capacitance tomography and laser shadowgraphy, the flow pattern in the pipe and the structure of the spray out of the nozzle is visualized. Meanwhile, the details of the temperature and pressure in the discharging system are acquired synchronously by the sensors with high sampling frequency. Conducting experimental teaching on this apparatus, students could observe directly the discharging process of fire suppressants, master the measurement methods of the related key parameters, and develop interdisciplinary concepts and innovative spirits.