In view of the many problems faced by the electronic signature service in the power industry, such as the increase of the media and types of storing digital certificates, the diversity of service modes of electronic signature, and the comprehensive support of the national secret algorithm, this paper proposes a scheme of the integrated electronic signature service platform. The platform adopts SDK interface to call its signature and verify signature, middleware and certificate service provide the interaction between application and digital certificate, realize the coexistence of multiple signature modes, meet the diversified electronic signature services of power users, improve the security of signature, and better serve the development of power business.