Tailings dam is a man-made hazard with high potential energy; dam failure would cause great losses to human lives and properties. However, the limitations of conventional reinforcement methods like geosynthetic make it easy to slide along the weak structural plane. In this paper, we innovatively added basalt fibre (BF) with different lengths (
l
) and contents (
ω
) into tailings to study its mechanical and permeation characteristics. The results indicate that BF can improve the shear strength (
τ
), cohesion (
c
) and compression index (
C
c
) of tailings, but it has little effect on internal friction angle (
φ
). When
l
is constant,
τ
,
c
and
C
c
are positively correlated with
ω
. One notable phenomenon is that
τ
and
c
do not constantly increase with
l
when
ω
is constant, but obtain the maximum under the optimal length of 6 mm. Moreover, when
ω
> 0.6%, permeability coefficient (
k
) is greater than that of the original tailings and the sensitivity of
c
,
φ
,
τ
,
C
c
,
k
to fibre content is greater than that of length. The research results facilitate the understanding of BF reinforced tailings, and could serve as references for improving the safety of tailings dam and other artificial soil slopes or soil structures.