Abstract: In this paper we present the security analysis on a multi-signature scheme based on the generalized conic curve (Lin-Wang-Li protocol) is presented, which exist the severe forgery problems. The security of the scheme is not based on any difficult issues such as the discrete logarithms on the generalized conic curve or the hardness of integer factoring. An adversary can forge the signature without solving any hard problems. In order to solve the existing problems, we improve the scheme is improved and a present our multi-signature scheme on the generalized conic curve is presented.