In order to explore the impact of biochar input on farmland surface albedo and soil thermo-physical properties，field plot experiments were conducted to analyze the changes of farmland surface albedo，soil temperature and soil thermo-physical properties under the influence of biochar during fallow period.Three treatments were set up，including the blank control group(CK)，and biochar applied at 1.0 kg·m-2·a-1(BC10)，and biochar applied at 4.0 kg·m-2·a-1(BC40)，with three replication for each treatment.It showed that:(1)Compared with CK treatment，the surface albedo of BC10 and BC40 treatments decreased by 11.7% and 23.5%，respectively(P<0.05).Soil moisture changes had the most significant impact on surface albedo，showing a significant negative correlation.(2)Biochar could significantly affect the temperature of the 0～2.5 cm soil layer，but had no significant effect on the temperature of the 5～10 cm soil layer.The main reason is that the decrease in thermal conductivity limits the transfer of soil heat.(3)Biochar had a significant influence on the thermal properties of soil.As the amount of charcoal increased，the soil heat capacity，thermal conductivity，and thermal diffusivity all showed a downward trend.Compared with the control，the heat capacity of the soil treated by BC10 and BC40 decreased by 4.1% and 11.2%，the thermal conductivity decreased by 5.56% and 18.17%，and the thermal diffusivity decreased by 4.3% and 15.9%，respectively.The greater the amount of biochar applied，the greater the drop in thermal property parameters. Under field test conditions，the change of water content had the most significant impact on thermal properties.As the soil moisture increased，soil heat capacity，thermal conductivity and thermal diffusivity all increased.