This paper is concerned with the study on an open problem of classifying conformally flat minimal Legendrian submanifolds in the
$(2n+1)$
-dimensional unit sphere
$\mathbb {S}^{2n+1}$
admitting a Sasakian structure
$(\varphi,\,\xi,\,\eta,\,g)$
for
$n\ge 3$
, motivated by the classification of minimal Legendrian submanifolds with constant sectional curvature. First of all, we completely classify such Legendrian submanifolds by assuming that the tensor
$K:=-\varphi h$
is semi-parallel, which is introduced as a natural extension of
$C$
-parallel second fundamental form
$h$
. Secondly, such submanifolds have also been determined under the condition that the Ricci tensor is semi-parallel, generalizing the Einstein condition. Finally, as direct consequences, new characterizations of the Calabi torus are presented.