The dynamic adsorption-desorption behavior of gallium in simulated sulfuric acid leach solution of fly ash on polystyrene resin (LX-92) was investigated by fixed bed device. The dynamic adsorption process was analyzed by Thomas, Yoon-Nelson, and Adam-Bohart empirical models. The results showed that decreasing the flow rate (Fad) and the initial concentration of gallium(III) (C0), increasing the bed height (Z) were conducive to improve the fixed bed adsorption efficiency and equilibrium adsorption capacity. According to experiments data, the optimum conditions for dynamic adsorption process was as follow: Fad=5.0 mL/min, C0=260 mg/L and T=55℃, and the maximum adsorption capacity was 56.65 mg/g. The elution rate of gallium could reach 94.40% at the conditions of 3.0 mol/L H2SO4 and 1.0 mL/min flow rate. After the process of adsorption and desorption, the concentration of gallium ions could be enriched more than 10 times. The dynamic adsorption behavior of gallium by the resin was well fitted by the Yoon-Nelson dynamic adsorption model. The corresponding equations of the dynamic adsorption rate constant KYN and the half-through time τ value constant with the initial Ga(III) ion concentration, flow rate, and bed height were established. The dynamic adsorption results would be used for engineering purpose of the of low-concentration gallium ions recovery.