Abstract: To investigate the mechanical properties of basalt fiber reinforced foam concrete, the quasi-static tensile and compressive tests were carried out on the prepared 52 groups of specimens, and the effects of basalt fiber volume fraction and fiber length on the tensile and compressive properties of specimens with different densities were experimentally studied. The test results show that the basalt fiber could significantly improve the tensile peak stress (maximum improvement of 737%) and peak strain (maximum improvement of 833%) of specimens. Due to the appearance of pseudo strain hardening phenomenon, the basalt fiber could effectively improve the tensile failure mode of the medium and high density specimens, so as to improve the tensile bearing capacity and deformation ability of specimens. It is found that tensile peak stress and peak strain increase with increasing the fiber volume fraction, and increase first and then decrease with increasing the fiber length. Furthermore, basalt fiber could change the compression failure mode of specimens with the observed trend from longitudinal splitting failure to oblique shear failure and transverse crushing failure, resulting in significant improvement of the compressive bearing capacity and energy absorption ability of low and medium density specimens. In addition, it is observed that increasing the fiber volume content will lead to an increase in the energy absorption (maximum improvement of 328%) of the specimen, which increases first and then decreases with increasing the fiber length.