Abstract: Taking cucumber ‘Pioneer Source to recognize 517’ as material, pot experiment and laboratory analysis method were used, the effects of the farming practices in nitrogen decreased nitrogen 20%,on the basis of applying three different crop straw to soil physical and chemical properties, soil enzyme activity and quality of cucumber and dry matter accumulation were studied, in order to provide reference for the growth of cucumber crop straw.The results showed that the available potassium, organic matter, total nitrogen, total potassium and total phosphorus were significantly increased by 28.40%-63.53%,8.81%-22.48%,5.38%-48.04%,0.51%-10.05%,13.94%-93.89%,respectively, and the electrical conductivity was decreased by 9.24%-61.12%.The activities of urease, cellulase, catalase, and alkaline phosphatase in soil increased by 4.07%-78.33%,1.66%-161.26%,0.30%-14.56%,2.22%-101.56% in 20% reduction combined with straw application.Vitamin C,soluble sugar and soluble protein increased by 11.78%-70.76%,33.07%-105.42% and 7.76%-129.03%,respectively, and nitrate decreased by 3.91%-34.36%.The dry matter accumulation of stem, leaf and melon of different crop straws was effectively increased, and soybean straws（N2S） was the highest.Based on the comprehensive analysis, 20% nitrogen reduction combined with straw application could improve soil properties and enzyme activities, improve fruit quality and nutrient accumulation of cucumber, which was a recommended rational nitrogen application method.