A potential acidic soil conditioner，which produced by calcination of iron mine tailings and by-product mica and dolomite，was alkaline and contains a considerable amount of beneficial elements required by plant growth such as potassium，calcium，magnesium and silicon.To investigate the application effects of the mineral conditioner in acidic soil area，an one-year field plot experiment was conducted in two locations.The soil pH，alkali-hydrolyzale nitrogen，available phosphorus，available potassium and the growth and yield of oilseed rape were analyzed after application of different amounts of the mineral conditioner.Five treatments were evaluated: no fertilization and no conditioner(T1)，recommended fertilization(T2)，and recommended fertilization with application of 750，1500 and 2250 kg/hm² conditioner respectively for T3，T4 and T5.Both experiments showed that:(1) in the treatments of the mineral conditioner application，the soil pH and the concentrations of available phosphorus and potassium in soil at different growth stages of oilseed rape were significantly increased compared with the treatment of recommended fertilization(P<0.05).And the differences had a tendency of increase with the increased amount of the mineral conditioner.While the concentrations of alkali-hydrolyzale nitrogen in soil had no obvious changes after the application of the mineral conditioner.(2) The mineral conditioner application promoted the growth and increased the yield of oilseed rape compared with the treatment of recommended fertilization，especially the yield components such as the number of first-order branches，number of siliques per plant and thousand grain weight.And the yield of oilseed rape increased significantly when the dosage of the mineral conditioner was 1500 kg/hm²(P<0.05).(3) Considering the benefits of the mineral conditioner application on soil nutrition，crop yields and its cost，the application dosage of 1500 kg/hm² showed more effective and more economical than the other two application dosages of 750 and 2250 kg/hm²，respectively.It can be seen that the calcination product of the iron mine tailings and by-product mica and dolomite，can be utilized as an efficient conditioner to improve soil acidification，supplement soil available nutrients and increase crop yield in acidic soil area.