In order to deeply understand nitrogen（N） transformation process and enzymatic response behaviors in the farmland black soil during non-growing season, the effects of different freezing-thawing factors（freezing and thawing temperatures, freezing-thawing cycles（FTCs） number, moisture regime） on microbial biomass N（MBN） content and protease and nitrate reductase activities were investigated in the farmland black soil with a laboratory simulation experiment. The results showed that the larger freezing-thawing temperature range from（-15～-12℃/2-5℃）and the reasonable FTCs number（6-15） and moisture regime（20%-30%） were the major driving factors affecting MBN content and protease and nitrate reductase activities of farmland black soil. With freezing temperature decreasing, protease activity first increased then decreased, MBN content significantly decreased being contrary to the changes of nitrate reductase activity in the FTCs-treated soils. With thawing temperature increasing, the MBN content and protease and nitrate reductase activities all had no significant changes in the FTCs-treated soils. With FTCs number increasing, MBN content and nitrate reductase activity both first increased then decreased, and protease activity significantly increased in the FTCs-treated soils. With moisture regime increasing, MBN content first increased then decreased, and protease activity significantly increased being contrary to the changes of nitrate reductase activity in the FTCs-treated soils. Therefore, it is preliminarily concluded that soil N transformation process and enzyme activities were significantly influenced by FTCs in the farmland black soil.