In order to investigate the effects of long-term application of blended controlled-release urea (CRF) on soil enzyme activities and nutrient status under straw returning condition to the field,soil samples ranging from 0 to 20 cm were collected from the field experiment of long-term positioning fertilization since 2008 at the rejuvenation stage,flag stage,filling stage and maturity stages of wheat in 2021.Without fertilized nitrogen as a control,the effects of CRF and normal urea (BBF),and four application levels that no nitrogen application (N 0 kg/hm²),reduced nitrogen application (N 120 kg/hm²,N1),conventional nitrogen application (N 240 kg/hm²,N2) and increased nitrogen application (N 360 kg/hm²,N3) on soil enzyme activities and soil nutrients in wheat season were studied under straw returning,and the correlation analysis of the indexes was conducted.The results showed that under the same nitrogen application level,soil sucrase activity and cellulase activity were increased by 9.6%~21.0% and 9.0%~31.5% under CRF treatment compared with BBF treatment,respectively.The soil nitrate nitrogen content in CRF treatment was significantly higher than that in BBF treatment at the rejuvenation and maturity stages of wheat,increasing by 23.2%~145.0%.At the rejuvenation stage,the soil NH₄⁺—N content under CRF2 treatment was significantly increased by 148.0% compared with that in BBF2 treatment.At maturity stage,the content of ammonium nitrogn in soil under CRF treatments was significantly higher than that of BBF treatments at all nitrogen application levels.Compared with BBF1 and BBF2,CRF1 and CRF2 treatments increased wheat grain yield by 9.8% and 12.4%,respectively.Soil urease and catalase activities were significantly positively correlated with the contents of soil total nitrogen,organic matter and nitrate nitrogen,while catalase and cellulase activities were significantly negatively correlated with phosphorus and available potassium contents.Straw returning combined with CRF increased soil enzyme activities at the middle and late growth stages of wheat compared with BBF,and was more conducive to the supply of available nitrogen at the early and late growth stages of wheat.Long-term application of straw returning combined with CRF significantly increased soil organic matter content,improved soil fertility retention and buffering,and improved soil fertility.Among them,the optimal treatment was CRF with conventional fertilizer application rate.