  The goal of this paper is to study the structure of split regular
BiHom-Leiniz superalgebras, which is a natural generalization of split regular
Hom-Leiniz algebras and split regular BiHom-Lie superalgebras. By developing
techniques of connections of roots for this kind of algebras, we show that such
a split regular BiHom-Leiniz superalgebras $\mathfrak{L}$ is of the form
$\mathfrak{L}=U+\sum_{\a}I_\a$ with $U$ a subspace of a maximal abelian
subalgebra $H$ and any $I_{\a}$, a well described ideal of $\mathfrak{L}$,
satisfying $[I_\a, I_\b]= 0$ if $[\a]\neq [\b]$. In the case of $\mathfrak{L}$
being of maximal length, the simplicity of $\mathfrak{L}$ is also characterized
in terms of connections of roots.
