Concentric-ring high gravity rotating bed is a new type of high gravity rotating bed. Liquid flooding is an important characteristic of hydrodynamics of high gravity rotating bed. The liquid droplets in the ring space between the liquid distributor and the inner edge of the rotor of the concentric-ring high gravity rotating bed are entrained by the gas. In terms of centrifugal force and drag force of gas that exerts the liquid droplets, a differential equation is established, from which a radial distance of the liquid droplets at radial velocity of the liquid droplets of zero is obtained. As the radial distance of the droplets at radial velocity of zero is less than that of the ring space, the entrainment flooding occurs. Thus, an entrainment flooding model of concentric-ring high gravity rotating bed was established. Experiments were carried out in a concentric-ring high gravity rotating bed with a rotor of 1000 mm diameter and 100 mm height using air-water system. Change of gas pressure drop between inlet and outlet of the concentric-ring high gravity rotating bed with superficial gas velocity was measured at various rotational speeds and superficial liquid velocities. The gas pressure drop increased slowly at first and then rapidly with increase of superficial gas velocity. The superficial gas velocity at flooding point was determined by both a derivation of gas pressure drop with apparent gas velocity and visual observation of a large amount of liquid entrained by gas at the gas outlet in the eye of the rotor. Thus, coefficient k of entrainment flooding model was obtained by the superficial gas velocity at flooding point and then coefficient k was correlated. Calculated values agreed well with experimental values, with an average deviation of 3.1%. The entrainment flooding model was superior to Sherwood's flooding model, and providing design basis for the industrial application of concentric-ring high gravity rotating bed.