Let V be a vertex operator superalgebra and G a finite automorphism group of V containing the canonical automorphism such that $V^G$ is regular.We classify the irreducible $V^G$-modules appearing in twisted V -modules and prove that these are all the irreducible $V^G$ -modules. Moreover, the quantum dimensions of irreducible $V^G $-modules are determined, a global dimension formula for V in terms of twisted modules is obtained and a super quantum Galois theory is established. In addition, the S-matrix of $V^G$ is computed.