The preparation, characterization, and uranium (VI) adsorption properties of tri-amidoxime modified marine fungus material (ZZF51-GPTS-EDA-AM/ZGEA) were investigated in this study. ZGEA was synthesized by four steps of condensation, nucleophilic substitution, electrophilic addition, and nitrile amidoxime and characterized by a series of methods containing FT-IR, TGA, SEM, and BET. Contrasted with uranium (VI) adsorption capacity of original fungus mycelium (15.46 mg g-1) that of the functional material (584.60 mg g-1) was great under the optimal factors such as uranium (VI) ion concentration 40 mg L-1, solid-liquid ratio 50 mg L-1, pH of solution 5.5, and reaction time 120 min. The above data were obtained by the orthogonal method. The cyclic tests showed that ZGEA had good regeneration performance, and it could be recycled at least five adsorption-desorption processes. The thermodynamic experimental adsorption result fitted Langmuir and Freundlich models, which explored monolayer and double layers of uranium (VI) adsorption mechanism, and the kinetic adsorption results were in better consistent with the pseudo-second-order and pseudo-first-order dynamic models (R2 > 0.999).