Solvent extraction of vanadium（V） from high alkaline solution using the modified quaternary ammonium salt as the extractant is studied. The effects of extractant concentration, DL-2-Octanol concentration, alkaline and vanadium concentration of feed, phase ratio, oscillation time and temperature on the extraction of vanadium are investigated. And the extraction distribution isotherm of vanadium is also plotted. Experimental results show that the single stage extraction rate of vanadium can reach 80 % and the saturated loading capacity for V2O5 can reach 5.85 g/L under the optimal conditions of alkaline of 1.5 mol/L,vanadium concentration of 3.57 g/L, phase ratio（O/A） of 2 ∶1, oscillation time of 8 min, room temperature, and the organic phase consists of 50 wt% Trioctadecyl Methyl Ammonium Chloride（CO32-type） ＋ 20 wt% DL-2-Octanol ＋ 30 wt% sulfonated kerosene. After five stages counter-current test, the extraction rate of vanadium can reach 99.4 % and the concentration of V2O5 left in the raffinate is less than 0.05 g/L.