Rapid analysis of uranium is useful for the exploration and exploitation of uranium ore, while traditional methods always require several hours for a single analysis procedure. Herein, a novel online extraction device that incorporates a heating unit was fabricated to efficiently extract the uranium from ore, followed by real-time ICP-MS detection. As a result, without sample pretreatment, the uranium content in two kinds of uranium ore can be obtained directly within 15 min with low sample consumption (1.0 mg), low energy consumption, and high recovery (90%). The present method provided a useful platform for the rapid quantitative analysis of uranium, which is beneficial for the improvement of the efficiency of exploration and exploitation of uranium.