Abstract: In the present study, the dissolution rules of various vanadium oxides in alkaline solution at different reaction temperatures, times and NaOH concentrations were studied, and the experimental conditions of separating the vanadium oxides with different valence states were determined.Subsequently, the V⁵⁺ content in the alkaline solution was determined by potentiometric titration, and the accuracy of detectingV⁵⁺ was determined.Based on the mentioned methods above, vanadium in different valence states in the blank roasting at different calcination temperatures and times were separated by alkali leaching, and the content of V⁵⁺ in the leaching solution was detected. The experimental results were summarized as follows: In the calcination process, the V⁵⁺ content began to rise at 600℃and tended to be stable at 700℃. The influence of time on V⁵⁺ content was not obvious below 700℃. When the temperature is above 700℃, the conversion rate of V⁵⁺ increased obviously with the increase of time, and tended to be stable after 3 hour.