Abstract: The absorber ball system is the reserve shutdown system of pebble-bed high-temperature gascooled reactor, which participates in the reactor reactivity control and keeps the reactor in sub-criticality. The discharge vessel is the first device through which millions of 6 mm absorber balls are pneumatically conveyed from the side reflector back to the ball storage vessel. The absorber balls are suspended and accelerated by the gas flow inside the discharge vessel, and the study on the conveying performance and the reliability of different discharge vessels is required. The numerical simulation of a new style fluidizing nozzle discharge vessel was performed, the velocity and the pressure distributions were showed. Meanwhile, an experimental study on the discharge vessel using normal temperature air as conveying medium was performed. The simulation result shows that the local resistance coefficient of the discharge vessel is 5.1, and the experiment result shows that the local resistance coefficient of the discharge vessel is 5.7. The results are acceptable for engineering application.