In order to explore the effects of tobacco stalk biochar organic fertilizer on soil main nutrients and humus substances，indoor soil cultivation experiment was conducted with organic fertilizer，tobacco stalk biochar organic fertilizer and tobacco stalk biochar.Eight treatments were set up，which were control treatment(CK，single application of organic fertilizer)，tobacco stalk biochar accounted for 10%(B10)，20%(B20)，40%(B40)，60%(B60)of organic fertilizer，and tobacco stalk biochar accounted for 100%(B100)，1/2 amount of tobacco stalk biochar(BH)，1/4 amount of tobacco stalk biochar(B2H).The results showed as follows:(1)compared with CK，tobacco stalk biochar effectively increased soil pH and the accumulation of soil available potassium，total carbon and total nitrogen，and the content of available potassium and total carbon in B100 treatment increased by 55.1%and 132.1%，respectively.The soil available phosphorus content increased with the increase of tobacco stalk carbon content，but the improvement effect of tobacco stalk biochar organic fertilizer was better than that of tobacco stalk biochar single application，among which B60 treatment was the largest(72.69 mg·kg-1)，B100 treatment was the second(46.76 mg·kg-1).However，the content of alkali-hydrolyzable nitrogen in soil was decreased by tobacco stalk biochar，and the content of alkali-hydrolyzable nitrogen in soil under B100 treatment was the lowest，which was reduced by 21.3%，compared with the control.(2)Tobacco stalk biochar increased the exchangeable Ca and exchangeable Mg content in soil，and the effect of tobacco stalk biochar addition was more stable than that of organic fertilizer alone with the extension of incubation time.(3)Tobacco stalk biochar significantly increased soil organic carbon and humin content.Compared with CK，B100 treatment increased organic carbon by 68.6%and humin by 147.8%，respectively.In B10～B60 treatment，humic acid content in soil was decreased with the increase of tobacco stalk biochar ratio.In B2H～B100 treatment，humic acid content was increased slightly with the increase of carbon application.The content of fulferic acid in soil was the lowest in B100 treatment，which had the highest amount of tobacco stalk biochar.In general，under the same amount of fertilization，organic fertilizer is beneficial to the improvement of soil alkali-hydrolyzed nitrogen，and promote the formation of humic acid and fulferic acid in soil.Tobacco stalk biochar was able to increase soil carbon，total nitrogen，available potassium，available phosphorus and exchangeable magnesium.In conclusion，organic fertilizer containing 60% tobacco stalk biochar(B60)could improve soil main nutrients and the formation of soil humus.