  Ouyang et al. proposed an $(n,n)$ threshold quantum secret sharing scheme,
where the number of participants is limited to $n=4k+1,k\in Z^+$, and the
security evaluation of the scheme was carried out accordingly. In this paper,
we propose an $(n,n)$ threshold quantum secret sharing scheme for the number of
participants $n$ in any case ( $n\in Z^+$ ). The scheme is based on a quantum
circuit, which consists of Clifford group gates and Toffoli gate. We study the
properties of the quantum circuit in this paper and use the quantum circuit to
analyze the security of the scheme for dishonest participants.
