The invention provides a device and a method for extracting uranium from high-density ore pulp. The device and the method are used for extracting uranium when the density of an ore pulp solution is higher that of resin. A part of the high-density ore pulp is filtered to obtain a clear solution used as a cleaner, and most of the ore pulp is used as an adsorption primary pulp. The adsorption primary pulp, the cleaner and the resin are added in the device at a certain speed to finally obtain adsorption tail pulp of which the uranium concentration meets the requirement and resin cleaned and loaded with uranium. The device adopts a trough adsorption device capable of treating the high-density ore pulp. The resin and the ore pulp reversely flow continuously and automatically among stages in a trough. The holdup fractions of the resin in all the stages can be controlled. When uranium in the high-density ore pulp is adsorbed, the ore pulp needs not to be diluted, so that the component concentration of an adsorption feed solution is improved; only a small amount of raw materials realize solid-liquid separation, so that the problem of difficulty in solid-liquid separation of the adsorption feed solution is solved; and new water is not required in cleaning, so that wastewater discharge is reduced, and the recovery rate of uranium is increased.