To improve white mud wet flue gas desulfurization technology, the influence of total dissolved solids (TDS) on desulfurization slurry oxidation was researched. The components of white mud slurry were measured by Inductively Coupled Plasma Mass Spectrometry(ICP-MS)and the experimental study on the effects of the main components in the slurry on sulfite calcium oxidation was carried out. The slurry oxidation mechanism of TDS was expounded and the experimental products and gypsum sample were analyzed by SEM. Results have confirmed the inhibition of TDS to calcium sulfate oxidation in white mud desulfurization slurry. The clusters of crystals were generated in experimental products, leading to dehydration difficulties. The soluble salt in the white mud slurry of plaster desulfurization gypsum is 50-100 μm, with perfect crystallization effect. TDS inhibits the oxidation of the white mud desulfurization slurry, but will improve the supersaturation of the solution and hence enable the gypsum crystal. The catalysis of Mn²⁺ was on longer effective with high TDS. The excessive content of calcium sulfite in slurry causes difficultities to some extent for the dehydration of white mud desulfurization by-products. Besides the concern on Cl^-, TDS should also be controlled in white mud desulfurization to gurantee the normal operation of the white mud desulfurization system.