Abstract: For many hard problems such as the word problem, conjugacy problem and root problem in the braid group, the paper introduced the basic concept of nature and important properties and difficult problems of the braid group.Based on of that, the designated verifier proxy signature scheme is proposed based on identity using conjugate search problem and the p-th root finding problem, and the exchangeable of the group operation between the elements in the left subgroup and the right subgroup of a braid group.Its security is analyzed and the result shows that this scheme is secure and effective, and has the nature of unforgeability.