Chemical precipitation method was applied in for separation and recovery of valuable metals molybdenum, vanadium and aluminum from alkaline V⁃Mo⁃Al solution. By the theoretical calculation and conditional experiments, the effects of precipitating agent dosage, temperature, pH value and deposition time on the precipitation separation of molybdenum and vanadium in alkaline solution were investigated detailedly. The results showed that when CaCl2 was used for vanadium precipitation, the reaction temperature was 80 ℃, the addition of CaCl2 was 1.1 times of the theoretical addition, the time was 1 h, and the pH was 12.9,over 95.3% of vanadium was precipitation recovered. When molybdenum was recovered by Ba(OH)2, under the optimum conditions of temperature 80 ℃, Ba(OH)2 dosage 1.1 times the stoichiometric amount, reaction time 60 min,the precipitation rate of molybdenum was up to 99.6%.