In order to solve the secure distribution problem and sub-key security issues in the existing secret sharing scheme, based on large integer factorization and discrete logarithm problems, a new sharing scheme is proposed, which is combined with Deffie-Hellman key agreement protocol. And then, security and performance analysis is made in this scheme. As the secret can be recovered with the shadows provided by participants and it is computationally difficult to get the sub-keys from the shadows, the sub-keys can be reused to share the multi-secret. While all information interactions are transmitted in plaintext. The proposed scheme has higher safety and effectiveness over the existing schemes and is more practical. keywords-secret sharing; plaintext transmission; sub-key