A fault-tolerant conference key distribution scheme based on mechanism of identity-based cryptography and (t,n) threshold secret sharing is proposed in this paper. This scheme is much different to traditional ones, its secret shadows are not brought from the sponsor of conference, but from each server's private key signature. By getting together these n secret shadows, the sponsor can construct polynomial. Any of conferees invited by the sponsor can request these secret shadows from t of these n servers, and then restitute conference key by them. In all courses of conference key distribution and reconstruction, every member's identity can be easily validated, so it can be prevented from all kinds of cheat.