Abstract: The preparation of V₂O₅ by the processes of sodium bicarbonate （NaHCO₃） for leaching and ammonium carbonate （（NH₄）₂CO₃） or ammonium bicarbonate （NH₄HCO₃） for vanadium precipitation was studied with vanadium slag clinker by calcified roasting as raw materials. The research mainly focused on the effects of leaching temperature,leaching time,leaching agent concentration and liquid-solid ratio on the vanadium leaching rate,and the conditions of leachate purification and vanadium precipitation were also investigated. The results show that more than 92% of leaching rate can be achieved under conditions as follows: leaching temperature 95 ℃,leaching time 120 min,concentration of Na HCO₃15.8% and liquid-solid ratio 3:1~4:1,and V₂O₅ which has the purity of 99.87% and satisfies the YB/T 5304-2011 standard can be obtained by adding sodium aluminate in the leachate for silicon removal with w_Al/w_Si= 0.6~0.8 and precipitating vanadium with （NH₄）₂CO₃ or NH₄HCO₃.