In order to reduce nitrogen fertilizer application and environmental pollution as well as improve fertilizer efficiency，the effects of fertilizer of silicon calcium potassium magnesium on the yield and nitrogen efficiency of fruit cucumber were studied under the condition of nitrogen reduction. Two kinds of fruit cucumber(“Bixi” and “Sunset”)were used as experimental materials. 8 treatments including two levels of nitrogen fertilizer application(normal nitrogen application and 30% reduction application)were set up in the greenhouse with 3 replicates for each treatment. After harvest，the fruit yield in each plot was measured，nitrogen use efficiency，agronomic nitrogen use efficiency and partial factor productivity for applied nitrogen were calculated. The content of alkali-hydrolysable nitrogen and nitrate in soil was determined. The results showed that，as compared with the control group，application of 30% reduced nitrogen fertilizer group caused the significant decrease in the plot yield and nitrate content of cucumber. The lowest plot yield was 45.47 kg. However，in the treatment group with fertilizer of silicon calcium potassium magnesium application，together with reduced nitrogen fertilizer amount by 30%，the fruit yield，nitrogen use efficiency of two kinds of fruit cucumber were significantly higher than those of the control group. The maximum plot yield was 61.75 kg. The highest partial factor productivity for applied nitrogen was 64.92 kg·kg-1，respectively，while the nitrate content were decreased significantly，and the lowest was 199.57 mg ·kg-1. After applying silicon calcium potassium magnesium fertilizer，the change rules of each index for two kinds of cucumber were similar. Above all，under the reduced amount application of nitrogen fertilizer，the application of silicon calcium potassium magnesium fertilizer can promote the growth of fruit cucumber in the early and middle stage，improve the yield and nitrogen use efficiency of fruit cucumber，and reduce the content of nitrate，as well as alleviate the environmental problems caused by excessive nitrogen application.