In order to reduce the loss of humus acid on purple soil and increase the fertility of purple soil in Longchuanjiang river basin,using laboratory simulation method,this paper studied the effects of different contents of biochar(CK,1%,3%,5%,10%)on the pH,electrical conductivity(EC),leachate volume,humic acid and fulvic acid concentrations in a batch of purple soil columns under simulated raining condition.The results indicated that the pH and EC of the leaching solution gradually increased with the increase of the biochar proportion during the 29 day experiment.Compared with CK,the water loss of purple soil decreased by 6.33%,10.13%,16.46% and 25.32% under different treatments of biochar(1%,3%,5% and 10%),respectively.The humic acid concentration and cumulative leaching loss decreased with the increase of biochar proportion.The fulvic acid concentration and cumulative leaching loss decreased with the increase of biochar proportion,except for 1% and 3% treatments.Under the proportion of biochar of 10%,the concentration and cumulative leaching loss of humic acid and fulvic acid on purple soil leaching solution were the least,the concentration and cumulative leaching loss of humic acid were 1.46 mg/L and 0.12 mg,the concentration and cumulative leaching loss of fulvic acid were 149.64 mg/L and 29.60 mg,which were beneficial to adsorb humic acid and fulvic acid and reduce their losses.