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In order to study the mode of application of biochar in the black soil area, a field runoff plot of 3° slope cultivated land in Northeast China was studied for a period of three years. In 2015, according to the amount of biochar applied, five treatments of C0 (0t/hm2), C25 (25t/hm2), C50 (50t/hm2), C75 (75t/hm2) and C100 (100t/hm2) were set up. The treatments were applied with the same amount of biochar in 2016 and 2017, respectively. The changes of soil physical and chemical properties, the effects of soil and water conservation and the effects of watersaving and yieldincreasing were studied after applying biochar for three consecutive years in black soil area. And a model was established based on an improved TOPSIS to comprehensively evaluate the application mode of biochar. The results showed that the soil organic carbon density, pH value and the applied amount of biochar presented a linear increasing trend, the soil bulk density and the applied amount of biochar showed a linear decreasing trend, and the longer the service life was, the more obvious the effect was. The field water holding capacity and the applied amount of biochar were increased linearly in the first year. The C100 treatment had the largest amount of water in the field, which was 3548%. And the field water capacity and applied amount of biochar during the twoyear and threeyear continuous applications showed a quadratic parabola changes. The parabola changes reached the maximum at C50 treatment, which were 36.20% and 36.24%. The threeyear annual runoff, annual soil erosion and applied amount of biochar were firstly reduced and then increased by the quadratic parabola. Continuous application of two years of 50t/hm2 biochar had the best reduction effect and antierosion effect. The application of biochar for three consecutive years increased soybean yield and water use efficiency, The highest increase in yield and water use efficiency in each year were C75 (21.8%, 25.3%), C50 (33.3%, 27.6%) and C50 (24.1%, 19.8%), respectively. Under the conditions of different biochar application rates and application years, the improved TOPSIS model can objectively and clearly describe the process of soil productivity changes, and summarize the proposed biochar application mode. That was, continuous application of 50t/hm2 biochar for two years gave the best improvement in soil productivity, which followed by 75t/hm2 for a year. The results of this research can provide a theoretical basis for practical production.