The effects of biochar application on the microbial community, enzyme activity and soil nutrient availability in dryland soils of central Guizhou were studied through pot experiment. The results showed that after applying 5%~15% (biochar/soil mass ratio) biochar to different types of dryland soils, the number of fungi, actinomycetes, bacteria and nitrifying bacteria, ammoniated bacteria and the activity of phosphatase, catalase and urease in yellow soil and yellow sand soil increased obviously, especially in yellow sand soil. The number of actinomycetes, fungi and nitrifying bacteria in the lime soil, as well as the activity of phosphatase and catalase increased significantly, but the number of ammoniated bacteria and urease activity decreased significantly. In addition, the content of available N, P, K, Ca, Mg and B in yellow soil and yellow sand soil increased in different degrees, but the content of available Fe, Mn, Cu and Zn decreased in different degrees. The content of available P, K, Fe, Mn, Cu and B in the lime soil increased in different degrees, but the available N, Ca, Mg and Zn in the lime soil decreased in different degrees. The content of available Zn in these three dryland soils all decreased obviously after applying biochar. The application of 5%~15% biochar in yellow soil, yellow sand soil and lime soil could obviously increase the yield of cabbage and lettuce, of which the yellow sand soil applied with biochar was the best in increasing yield, followed by lime soil. There were significant differences in the changes of soil available nutrients among different types of dryland soils after applying biochar. When applying biochar, a certain proportion of nitrogen, phosphorus, potassium and appropriate amount of trace element fertilizers should be used according to soil characteristics, which could promote the growth of crops.