In order to explore the effect of applying biochar on the posteffects of soil hydrodynamic parameters on different slopes, the experimental study on soil hydrodynamic effects was carried out for two consecutive years after the application of biochar under three kinds of terrain slope conditions. The effects of biochar applied to different slopes on soil water constant, soil water characteristic curve, specific water capacity, unsaturated hydraulic conductivity K(h) and unsaturated diffusion rate D(θ) were investigated. The results showed that the application of biochar could increase the soil water holding capacity and saturated water content in the same year and the next year, and the growth rate was increased with the increase of slope. Biochar factors had significant effects on soil water constants within two years (P<0.015), while slope factors had no significant effect (P>0.05), which meant that biochar factors were more pronounced. Within two years, the soil moisture content was increased under various soil suction conditions, soil water holding capacity was increased, and it was positively correlated with slope of terrain and negatively correlated with age. Biochar increased the soil specific water capacity within two years, and the water supply capacity was strengthened, the maximum water capacity increase was 1830207×10-3cm3/cm4. The slope of terrain had no obvious effect on K(h), but the application of biochar could increase K(h) and the soil water conductivity was enhanced. In 2016 and 2017, K(h) was increased by a maximum of 239.61% and 164.04%, respectively. The application of biochar could reduce D(θ) and inhibit the horizontal movement of soil moisture. As the increase of slope of terrain, the suppression effect was enhanced. The effect of biochar application on the soil hydrodynamic parameters in the first year was greater than that in the next year. The research results can provide a theoretical basis for the protection and utilization of agricultural soil and water in sloping farmland in the black soil region of Northeast China.