Abstract: In order to study the mechanical properties of bundled basalt fiber (BBF) reinforced concrete, cube compressive strength, splitting tensile strength and fracture toughness experiments of fiber reinforced concrete with different fiber lengths (12 mm, 18 mm, 24 mm), volume fraction (0.1%, 0.2%, 0.3%) and types (bundled basalt, chopped basalt and polypropylene) were carried out. And the microstructure was observed by scanning electron microscopy. Results show that the effect of BBF on compressive strength of concrete is not obvious; when the fiber length is 24 mm and the dosage is 0.2%, the maximum increase of tensile strength is 26.65%. With the reinforcement index (RI) increases, the tension-compression ratio of BBF concrete tends to increase, and when RI gets to 24, the tension-compression ratio is 1.39 times that of NC. Incorporation of BBF generally increases three-point bending peak load, initiation toughness and unstable toughness of concrete, in which the maximum increase rate at 0.3% are 53.66%, 47.06% and 151.03%, respectively. Scanning electron microscopy shows that a large number of hydration products are attached to surface of BBF, which are closely bonded to cement paste and have no obvious interface transition zone with matrix, effectively inhibiting propagation of micro-cracks.