A pot experiment was conducted to evaluate the effects of biochar application onsoil physiochemicalproperties， enzymeactivities，microbial communities and the heart rot of pineapple under continuous cropping. Four biochar levels of0%，0.4%，0.8%，1.2%(remarking as B0，B0.4，B0.8，B1.2treatments，respectively)were set up. The results showed that compared with B0treatment，the soil pH of B0.4，B0.8 and B1.2 treatments significantly increasedby0.15，0.33 and0.21，respectively，and the contents of soiltotal nitrogen，alkalinenitrogen，availablephosphorus，available potassium and organic matter increasedsignificantly，while there were no significant increase in the contents of soil total phosphorus and total potassium. Under the B0.4，B0.8 and B1.2treatments，the content of soil microbial biomass carbon significantlyincreased by23.14%，57.28% and 48.49% compared with B 0treatment，and the content of soil microbial biomass nitrogensignificantly increased by53.71%，153.34% and144.24%，respectively，while the soil microbial biomass carbon/microbialbiomass nitrogen value significantly decreased. Inaddition，biochar application significantly increased the number of bacteria and actinomycetes in pineapple continuous croppingsoil，and enhanced the activities of soilurease，proteinase，acidphosphatase，catalase，sucrase andcellulase，while significantly reduced the number of fungi and the incidence rate ofpineapple heart rot.Therefore，biochar application could effectively improve the pineapple continuous croppingsoil，and the optimum results were observed at B0.8 treatment.