Abstract: The effect of basalt fiber (BF) on the mechanical properties and toughness of basalt fiber reinforced spray concrete (BF/SC) was studied through the experiment. The microstructure of BF/SC was studied by SEM and nuclear magnetic resonance (NMR).The results show that the compressive strength, splitting tensile strength and flexural strength of BF/SC are significantly increased by adding BF. Compared to the plain SC, the flexural strength of BF/SC with 3 kg/m³ and 7.5 kg/m³ are better, and are energy absorption capacity are 2.42 times and 2.69 times as high as the plain SC, respectively. BF has a good dispersion rate in the SC, and displays reasonable bonding within the SC substrate. A proper amount of BF effectively inhibits the formation of large volume pores, in which the proportion of the large pore size of 3 kg/m³ BF/SC is only 0.25%, and the addition of excessive BF leads to an increase of fiber agglomeration and porosity. At the same time, the optimum content of fiber is found to be 3 kg/m³.