Extraction of aqueous uranium element for practical applications has drawn growing attention due to its significance for both green energy acquirement and ecological environment remediation. Herein, the liquid metal droplets produced by a facile ultra-sonication process are found to be able to capture aqueous uranyl ions with a maximal adsorption capacity up to 237 mg g (1483 mg cm), and further to reduce them into insoluble UO nanoparticles (2–5 nm in diameter). With the homogeneous immobilization of UO nanoparticles, the ultra-thin shell of liquid metal droplets exhibits a high catalytic activity towards electrochemical reductions e.g., CO reduction. The liquid metal core, when supporting on the electrodes, also offers the efficient electro-transporting pathway for electrochemical reaction. With a high formate selectivity, a faradaic efficiency ≥91.4 % and a generation rate as high as 988.9 mmol gh of C1 products (i.e., CO and formate) are achieved in the CO reduction. Thus, this study may offer not only a unique platform of liquid metal nanodroplets for extracting uranium from water, but also a novel route of fabricating high-efficiency electrochemical catalysts for CO conversion.