The dissolved metal ions have a significant effect on the wettability of mineral surface in flotation slurry. In this work, the composition and characteristic of phosphate ore raw (R), flotation concentrate (FC), and flotation tailing (FT), the dissolution of metal ions from mineral surface and its effect on mineral surface wettability were investigated. The results of the dissolution test indicated that the concentrations of Ca2+ and Mg2+ are high (FT > R > FC), while Fe3+ and Al3+ were low in the slurry. H3PO4, as the slurry pH regulator, has the weakest dissolved ability of metal ions from mineral surface compared with HCl, HNO3 and H2SO4. The surface tension tests revealed that metal ions will combine with NaOL in the slurry, causing the consumption of NaOL. The contact Angle tests performed that some of NaOL adsorption sites on the FC and FT surface were covered the hydrolysates of Fe3+ and Al3+, which inhibited the hydrophobicity of the FC and FT surfaces. Ca2+ and Mg2+ consumed part of NaOL in the slurry, inhibiting the hydrophobicity of the FT surface. However, the adsorption of Ca2+ and Mg2+ on the FC surface increased the adsorption of NaOL, which enhanced the hydrophobicity of the FC surface.