How to protect the security of vital data is one of the most important issues of the database security. An efficient method is to divide the vital data into multiple parts that are stored among a group of servers by secret sharing technique. In this paper, we propose a publicly verifiable dynamic sharing protocol for data secure storage. In this protocol, the important data can be publicly verifiably shared among multiple servers, at the same time, the protocol can dynamically recover the bad shares in the system if some servers are attacked. Different from previous protocols, the new protocol is not only efficient but also practical in many circumstances because all operations can be verified by everyone not only shareholders.