由于ＲＳＡ的秘密钥ｄ∈Ｚφ（ｎ），以前的门限ＲＳＡ密码体制的秘密共享方案都是以环Ｚφ（ｎ）为背景结构建立的，但这会遇到固有困难：Ｚφ（ｎ）不是域且φ（ｎ）必须保密．本文提出一种新的门限ＲＳＡ密码体制，用一般大素域代替环Ｚφ（ｎ）作为门限方案的背景结构，从而完全避开了上述困难． Due to RSA’s secret key d∈Zφ (n), the secret sharing scheme of the previous threshold RSA cryptosystem is built around the ring Zφ (n) as a background structure, but this encounters an inherent difficulty: Zφ (n) is not a domain And φ (n) must be kept secret. In this paper, a new threshold RSA cryptosystem is proposed, which replaces the ring Zφ (n) as the background structure of the threshold scheme with a generalized prime domain, completely avoiding the above difficulties.